EP4655152A1 - Extrusion head for additive manufacturing - Google Patents

Abstract

The invention relates to an extrusion head (1) for additively manufacturing a product, preferably on the basis of the fused filament fabrication method, comprising at least one material feed unit (2) for feeding at least one extrusion material (3), preferably in filament form, a cutting device (4) for the at least one extrusion material (3), at least one displacement unit (6) having at least two liquefier assemblies (7), wherein the at least one extrusion material (3) can be introduced into a first liquefier assembly and the top end of the extrusion material (3), cut off by the cutting device (4), can be introduced into a second liquefier assembly, the at least one displacement unit (6) being rotatable, particularly rotatable in the manner of a revolving head, and/or the extrusion head (1) being inclined or inclinable, preferably relative to the longitudinal axis of the extrusion head (1).

Description

Extrusion head for additive manufacturing The present invention relates to an extrusion head according to the preamble of claim 1. The invention also relates to a method and/or a use for producing a product by means of at least one such extrusion head. In the course of manufacturing products by additive manufacturing processes, for example fused filament fabrication, i.e. FFF method, there are a large number of different requirements. It is desirable that products with complex shapes are manufactured. Since in the field of additive manufacturing the products to be manufactured are produced piece by piece, specifically layer by layer, it is often difficult to produce complex shapes with high processing speeds and high processing accuracy. If more than one processing material must or should be used for a product, many manufacturing devices with which these products are manufactured reach their process-related limits. This can be the case, for example, if a product is to be manufactured from a first material A, whereby the product has undercuts due to its complex shape that cannot be manufactured from a second material B in the course of a layered construction without support structures. It can also be provided to construct a product from several materials or to offer the possibility of using a cleaning material. It is already known from the prior art, such as from EP 3725 497 A1, that more than one material can be processed within a device for additive manufacturing. It is also known in the state of the art that a cutting device can be provided in addition to an extrusion device. Such a cutting device cuts off the material intended for additive manufacturing, which is often in the form of a filament, after extrusion. Many challenges for additive manufacturing processes arise from the fact that they now find a wide range of applications in the industrial sector. In contrast to the private sector, in which small do-it-yourself devices are often used, the requirements in terms of efficiency, accuracy, process stability, temperature limits, spatial limits, product sizes and the like increase with use in the industrial sector. In order to ensure that the economic efficiency of the complex manufacturing process does not suffer, or at least not unduly, from the increased performance and the more difficult mechanical and chemical stresses, it is essential that additive manufacturing systems are designed to be as process-reliable, cost-effective, easy to maintain and low-maintenance as possible. A specific challenge for an additive manufacturing process in the industrial sector is to develop a highly efficient, very precise and, above all, process-reliable fused filament fabrication system for high ambient temperatures and nozzle temperatures that meets the high standards of the industrial sectors of aerospace, railway and automotive. To process high-performance plastics such as polyetheretherketone (PEEK) in large quantities, high nozzle temperatures, well above the melting temperature, of up to 440°C, are required. To ensure that the crystalline structure of the plastic is formed correctly so that the extrusion material has the highest possible strength, to keep heated construction spaces at temperatures of around 220°C to even 250°C constant and homogeneous. The current state of the art has various disadvantages. On the one hand, an extrusion material is often not cut cleanly or reliably, but is additionally deformed during a cutting process. This is particularly disadvantageous if a cut extrusion material, for example a filament, is bent and is to be fed back into a guide for further processing after cutting. On the other hand, cutting can lead to spider web-like thread formation because the softened extrusion material is not cut cleanly or reliably. Another specific challenge for an additive manufacturing process in the industrial sector is that materials often have to be changed. This can be the case, for example, when multi-component products are to be manufactured. Multiple materials also make sense if a product is made from a construction material with undercuts, whereby the undercuts are to be supported by a support structure with another material, namely a support material. Such material changes pose particular challenges for a fast, trouble-free and precise manufacturing process. Another specific challenge for an additive manufacturing process in the industrial sector is to produce products as quickly as possible with a sufficiently high level of precision. Since a fast manufacturing process usually comes at the expense of the precision of the products manufactured and, conversely, high precision results in a slower production speed, further developments are necessary in this regard. The object of the present invention is therefore to at least partially remedy the disadvantages of the prior art and to provide an extrusion head that is improved compared to the prior art and is characterized in particular by more flexible application options for extrusion materials and/or high precision with a high production speed and/or a cleaner cutting process for the extrusion material and/or higher process reliability. The object is also to provide a method and/or a use for producing a product with an extrusion head that is improved in this way. This object is achieved by the features of claims 1 and 10. This object is achieved by means of an extrusion head according to claim 1, namely by providing an extrusion head for additive manufacturing, preferably for the fused filament fabrication method, of a product comprising at least one material feed unit for feeding at least one extrusion material, preferably in filament form, a separating device for the at least one extrusion material, at least one offset unit with at least two liquefier units, wherein the at least one extrusion material can be introduced into a first liquefier unit and the upper end of the extrusion material severed by the separating device can be introduced into a second liquefier unit, wherein the at least one offset unit is rotatable, in particular rotatable as a turret head, and/or the extrusion head is tiltable or inclined, preferably with respect to the longitudinal axis of the extrusion head. In a preferred embodiment, it can be provided that the offset unit is rotatable relative to the material feed unit, the rotation axis of the offset unit being parallel to the longitudinal axis of the extrusion head or, in other words, parallel to the Z axis. In a preferred embodiment, it can be provided that the extrusion head is tiltable relative to a part to which the extrusion head is attached, in particular relative to the support bracket, the tilt axis of the extrusion head being transverse, preferably orthogonal, to the longitudinal axis of the extrusion head or, in other words, transverse, preferably orthogonal, to the Z axis. The longitudinal axis of the extrusion head is understood here to be an imaginary axis that runs essentially from the top of the support bracket to the bottom of the support bracket. The bottom of the support bracket is the side facing the offset unit and the top of the support bracket is the side oriented opposite the bottom. In other words, the longitudinal axis can also be referred to as an applicate, in the direction of which the height of the support bracket can be defined. In other words, the longitudinal axis can be parallel to the Z axis in the Cartesian coordinate system or to the Z axis in Figures 1 to 10. By designing the offset unit in the form of a rotatable part, in particular a rotatable turret head, the offset unit can be moved past the at least one separating device and/or the condenser units can be changed in a particularly simple, cost-effective and space-saving manner. The combination of a rotatable offset unit and a tiltable extrusion head can thus be used easily, quickly and The existing condenser units can be changed in a process-safe manner to feed them with one or more extrusion materials in order to then produce a product using contact-free printing. If the various condenser units have different nozzle diameters or nozzle nominal widths, an improved ratio between precision and production speed can be achieved by changing the condenser units easily, quickly and reliably using the rotatable and tiltable extrusion head. In this way, parts of the product that have to meet high precision requirements, such as external contours, can be manufactured with a condenser unit with a small nozzle nominal width at a lower production speed, whereas parts that do not have to meet such high precision requirements, such as the filling of precise external contours, can be manufactured with a condenser unit with a large nozzle nominal width at a higher production speed. The solution described above therefore enables cutting and/or a change of the condenser units and/or a change of the nozzles and/or a change of the extrusion materials to be carried out in a process-safe manner. This also avoids contamination and/or damage caused by the otherwise necessary withdrawal of the already softened or partially liquefied extrusion material. After the cut, the extrusion material is introduced into one of the liquefaction units for further processing and is then fed to the nozzle. If there is already a remaining piece of extrusion material in the liquefaction unit into which the cut extrusion material is introduced, the The remaining piece is also carried forward by the newly introduced extrusion material. The fused filament fabrication method (FFF method) is an additive manufacturing process. The term fused deposition modeling (FDM method) is used synonymously with the FFF method. The FFF method is a 3D printing technique and is generally considered an additive manufacturing process. A product is built up layer by layer from a meltable extrusion material. The extrusion material can be a plastic, a fiber-reinforced plastic, a composite plastic and/or a metal. Further advantageous embodiments of the extrusion head are defined in the dependent claims. According to a preferred embodiment of the extrusion head, it is provided that the separating device has at least one blade element, whereby the extrusion material can be guided to the at least one blade element and severed at a severing point by an almost gap-free passage of the at least one offset unit past the at least one separating device. The almost gap-free passage of the at least one offset unit past the at least one separating device is understood here to mean that at least at one point between the at least one offset unit and the at least one separating device and/or the at least one blade element, a cutting gap with a maximum distance of 50% of the nominal diameter of the extrusion material, preferably in filament form, preferably 25%, particularly preferably only 12% of the nominal diameter of the extrusion material is present in filament form. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element can be or is attached to or in the at least one material feed unit or is provided as a component of the material feed unit. Due to the almost gap-free passage of the at least one offset unit past the at least one separating device and due to the blade element attached to or in the at least one material feed unit, the extrusion material can be cut cleanly with the blade element without the extrusion material additionally deforming excessively, for example bending. This means that part of the extrusion material remains in the material feed unit and the other part of the extrusion material remains in a first liquefaction unit of the offset unit. Subsequently, the upper severed end of the extrusion material can be introduced into a second liquefaction unit either by moving the at least one offset unit past the at least one material feed unit or by moving the offset unit back past the at least one material feed unit into the first liquefaction unit. In any case, the extrusion material is essentially not deformed away from the point of severance. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is round and/or square. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is designed as a flat Plate or as a block or as a flat ring or as a sleeve. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element is connected to the at least one material feed unit by a blade connection device, preferably wherein the blade connection device can be released without causing damage. In a preferred embodiment, it can be provided that the cutting gap can be adjusted discretely and/or continuously by releasing the blade connection device, then by moving the at least one blade element, preferably along a wedge, and then by locking the at least one blade element by means of the blade connection device that can be released without causing damage. According to a preferred embodiment of the extrusion head, it is provided that the at least one blade element has at least one straight and/or curved cutting edge with a cutting surface underside and a cutting surface upper side, wherein in the state of the at least one blade element attached to or in the material feed unit, the underside of the at least one blade element and the cutting surface underside face the offset unit and the top of the at least one blade element and the cutting surface upper side face away from the offset unit. In a preferred embodiment, it can be provided that a multi-blade blade element can be provided, in which at least one cutting edge can be used in a first installed state and can be changed positionally in a in the further installed state, a further cutting edge can be used. In a preferred embodiment, it can be provided that at least one blade element can be exchangeable. According to a preferred embodiment of the extrusion head, it is provided that the lower side of the cutting surface and the upper side of the cutting surface are arranged at an angle to one another, preferably enclosing an angle of up to 55°, in particular a very acute angle of 20 to 30°. According to a preferred embodiment of the extrusion head, it is provided that the lower side of the cutting surface and/or the upper side of the cutting surface have at least two cutting surface sections, the first cutting surface section being adjacent to the cutting edge and the second cutting surface section not being adjacent to the cutting edge. In a preferred embodiment, it can be provided that at least one of the cutting surfaces, i.e. the lower side of the cutting surface and/or the upper side of the cutting surface, can have different surface sections with different cutting angles. In this way, the cutting surface profile can be additionally varied, whereby a cutting surface section that borders a cutting edge can have a steeper or flatter angle in contrast to a cutting surface section behind it that does not border the cutting edge. In another preferred embodiment, it can be provided that the blade element can have a curved or an approximately curved cutting surface profile due to several cutting surface sections. According to a preferred embodiment of the extrusion head, it is provided that the material feed unit has at least one inlet line for the at least one extrusion material, wherein, in the state of the at least one blade element attached to or in the material feed unit, the at least one inlet line runs within the material feed unit up to an area in front of, in particular up to, the at least one blade element. According to a preferred embodiment of the extrusion head, it is provided that, in the state of the at least one blade element attached to or in the material feed unit, the inlet line ends in an area between the blade element bottom and the blade element top. In an embodiment in which the inlet line extends to the blade element and/or to an area between the blade element bottom and the blade element top, the distance in which the extrusion material is not guided or at least not guided from all sides of the circumference of the extrusion material is kept to a minimum. This also minimizes the risk of deformation of the extrusion material away from the actual cut. Particularly in cases where the extrusion material is in the form of a filament, deformation of the extrusion material, in particular bending, represents an increased risk in terms of the process reliability of cutting and further processing of the extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the introduction line has at least one guide recess which extends to the separating device and through which the extrusion material is at least partially exposed. In a preferred embodiment, it can be provided that the introduction line has at least one guide recess, which can run up to an area in front of the separating device and through which the extrusion material is at least partially exposed. According to a preferred embodiment of the extrusion head, it is provided that the introduction line has at least one projection, wherein in the state of the at least one blade element attached to or in the material feed unit, the at least one projection protrudes into an area between the blade element bottom and the blade element top, wherein preferably two projections are provided and in the state of the at least one blade element attached to or in the material feed unit, the two projections form a guide recess, in particular a groove, preferably a transverse groove, in an area between the blade element bottom and the blade element top. With the help of one or more projections of the introduction line, the extrusion material can be guided from at least one or more sides into an area between the bottom of the blade element and the top of the blade element. In a preferred embodiment, it can further be provided that the extrusion material is guided almost to the cutting edge due to the shape of the at least one projection and/or the shape of the at least one projection surface facing the extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the introduction line is a separate component is present within the material feed unit or is a component of the material feed unit. In a preferred embodiment, it can be provided that the inlet line can consist of thermally treated metals, preferably tempered, hardened or nitrided steel, and/or partially of at least one sintered material, preferably tungsten carbide or ceramic, and/or can be coated, preferably with a tungsten sulfide coating. These materials represent wear-resistant materials and/or coatings, the use of which can be particularly advantageous for components subject to high stress, such as for the inlet line. According to a preferred embodiment of the extrusion head, it is provided that at least one conveying device of the material feed unit is provided for feeding the at least one extrusion material, wherein the at least one conveying device is designed to at least partially return the, preferably severed, at least one extrusion material within the material feed unit. By means of a conveyor device that can move the extrusion material both forwards and backwards, in other words, can not only extrude the extrusion material but also feed it back again, it is possible to straighten the extrusion material by pulling it back into the feed line. This is particularly useful if, despite everything, there should be a slight deformation of the extrusion material away from the cut. According to a preferred embodiment of the extrusion head, it is provided that the at least one offset unit has at least one receiving device, preferably at least two Receiving devices, particularly preferably one receiving device for each condenser unit. In a preferred embodiment, it can be provided that the at least one receiving device of the at least one offset unit can be formed on the drive wheel of the at least one offset unit for displacing the offset unit relative to the material feed unit on the side facing the material feed unit, preferably by countersunk holes. In a preferred embodiment, it can be provided that the at least two receiving devices of the at least one offset unit can be formed on the at least two further feed lines, in particular heat break lines, on the side facing the material feed unit, preferably by countersunk holes. In a preferred embodiment, it can be provided that the at least one receiving device can be present as a separate component within the offset unit or can be a part of the offset unit. In a preferred embodiment, it can be provided that the at least one receiving device on the side facing the material feed unit, preferably on and/or inside the drive wheel, can be designed as a flat plate, as a flat ring or as a sleeve with preferably a countersunk hole. In a preferred embodiment, it can be provided that the at least one receiving device is made of at least one thermally treated metal, preferably of tempered, hardened and/or nitrided steel, and/or partially of can consist of at least one sintered material, preferably tungsten carbide or ceramic, and/or can be coated, preferably with a tungsten sulfide coating. According to a preferred embodiment of the extrusion head, it is provided that at least one cooling device is provided for cooling the at least one offset unit and/or the at least one extrusion material and/or the separating device and/or the at least one blade element and/or the at least one conveying device and/or the at least one extrusion actuator and/or the offset actuator and/or at least one bearing and/or at least one seal and/or at least one convection protection. An actuator is a component or a mechanism for converting energy, for example electrical energy or pressure energy, into movement, for example kinetic energy, and can be designed in particular as a motor, particularly preferably as an electric motor. A cooling device can be provided so that the extrusion material can always be cut reliably in the solid state at high nozzle temperatures and processing temperatures, preferably at a temperature below the melting temperature, the softening temperature or the glass transition temperature, and introduced into one of the condenser units. This can be particularly useful if heat, for example generated by the heating blocks of the condenser units, migrates up to the cutting point as a result of diffusion and/or conduction and/or convection, particularly along the extrusion material. The extrusion material is heated from the nozzles via the condenser units to the cutting point and thus softened, which means that Cutting or severing the extrusion material can result in a spider web-like thread formation. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device is part of the material feed unit and/or the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device has one or more bores and/or grooves, in particular straight and/or curved grooves, and/or channels, in particular straight and/or curved channels, within the material feed unit and/or the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device has one or more coolant interfaces and/or cooling rotary feedthroughs. Usually, two coolant interfaces are provided for supplying coolant, one for supplying and one for discharging the coolant. Any number of coolant interfaces are possible, which can form either one cooling circuit or several cooling circuits. In a preferred embodiment, it can be provided that the at least one offset unit can be designed as a cooling rotary feedthrough. In a preferred embodiment, it can be provided that at least one of the existing coolant interfaces can be arranged within the offset unit. In a preferred embodiment, it can be provided that one or more supply lines of the at least one coolant interface, which is arranged within the offset unit, can run at least partially within the offset unit essentially parallel to the axis of rotation of the offset unit. Preferred embodiments of the extrusion head can advantageously, in particular by using a cable feedthrough designed as a slip ring and/or a distributor and/or a cooling block designed as a cooling rotary feedthrough, allow the offset unit to rotate continuously without causing the lines to fail, for example by tearing off the lines. In the case that the material feed unit has a substantially square shape, a cooling device with four holes can be provided, for example, which are each sealed to the outside with closure means. In this way, a square cooling path is created that can be connected to a coolant interface. In the case that the offset unit has a substantially hexagonal shape, a cooling device with six holes can be provided, for example, which are each sealed to the outside with closure means. In this way, a hexagonal cooling path is created that can be connected to a coolant interface. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device is arranged at least partially in the area after, preferably directly after, the cutting point of the at least one extrusion material. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device cools by means of a cooling medium, wherein the cooling medium is preferably gaseous and/or liquid. According to a preferred embodiment of the extrusion head, it is provided that the at least one cooling device represents a continuous cooling loop, preferably wherein the continuous cooling loop runs through both the material feed unit and the offset unit. According to a preferred embodiment of the extrusion head, it is provided that the separating device with the at least one blade element is a component of the material feed unit or is connected to the material feed unit and the at least one cooling device is a component of the material feed unit or is connected to the material feed unit. According to a preferred embodiment of the extrusion head, it is provided that the at least one offset unit is rotatable in two directions in one plane and/or the extrusion head is tiltable in at least two directions starting from a vertical starting position. The vertical starting position is understood to mean the position of the extrusion head which is shown in Figures 1 to 3, 28 and 34. In the vertical starting position, the rotation axis of the offset unit and the longitudinal axis of the extrusion head are parallel to each other. In other words, the rotation axis of the offset unit can be orthogonal to the horizontal top or bottom of the support console. In other words, the inclination angle of the inclination actuator can be set to 0 ^. In other words, all nozzles of the condenser units can be located in a horizontal plane. According to a preferred embodiment of the extrusion head, it is provided that the extrusion head can be tilted at least in one plane, in particular with respect to the longitudinal axis of the extrusion head on two sides within a plane. In a preferred embodiment of the extrusion head, it can be provided that the extrusion head can be connected to a support bracket by means of a tilt shaft, in particular with a key connection and a groove nut, and can be tilted via a tilt actuator, preferably relative to the support bracket, preferably wherein the extrusion head can be dismantled as a whole unit from the support bracket, preferably from the tilt shaft, by loosening the groove nut. In a preferred embodiment of the extrusion head, it can be provided that the tilt shaft can be provided as a component of the tilt actuator, in particular an electric motor, and/or can be connected or connectable to it. In a preferred embodiment of the extrusion head, it can be provided that the support bracket can have an energy transmission device, in particular a belt transmission, spur gear, planetary gear or worm gear, wherein the inclination shaft and the inclination actuator can be connected to the energy transmission device. In a preferred embodiment of the extrusion head, it can be provided that the inclination angle of the extrusion head at least in one plane, in particular the angle of rotation of the inclination shaft about its axis of rotation, preferably by Adjusting screws as an adjustable stop for the inclination shaft, can be discretely and/or continuously adjustable. In a preferred embodiment of the extrusion head, it can be provided that the support bracket can be connected to a travel system or can be provided as a component of the travel system, preferably in order to move the extrusion head in at least one direction. In a preferred embodiment of the extrusion head, it can be provided that the support bracket can have a spindle nut or can be provided as a component of the support bracket, wherein the spindle nut can be connected to a threaded spindle, in particular of the travel system, preferably in order to move the extrusion head in at least one direction. According to a preferred embodiment of the extrusion head, it is provided that the offset unit has at least two, preferably six, liquefier units, wherein a first extrusion material can be extruded by a first set of the existing liquefier units and a second extrusion material can be extruded by a second set of the existing liquefier units. In a preferred embodiment, it can be provided that the offset unit can have six condenser units, whereby three condenser units can represent the first set and the remaining three condenser units can represent the second set. In another preferred embodiment, it can be provided that the offset unit can have a different number of condenser units than stated in the previous embodiments. In another preferred embodiment, it can be provided that the condenser units of the first set can be arranged directly adjacent to one another and the condenser units of the second set can be arranged directly adjacent to one another. According to a preferred embodiment of the extrusion head, it is provided that the at least two condenser units have nozzle channels, wherein the at least two condenser units or the nozzle channels are arranged inclined to one another and/or to a rotation axis of the offset unit. According to a preferred embodiment of the extrusion head, it is provided that at least one locking means is provided, wherein at least one position of the offset unit relative to the material feed unit can be determined by the at least one locking means. In a preferred embodiment, it can be provided that the at least one locking means can be designed to be operated mechanically and/or electromechanically and/or pneumatically and/or hydraulically and/or electromagnetically. In a preferred embodiment, it can be provided that a locking recess can be provided for each locking means. In a preferred embodiment, it can be provided that the at least one locking means can be designed to be releasably lockable. In a preferred embodiment, it can be provided that the at least one locking means can be provided as a resilient pressure piece, in particular a ball pressure piece and in combination with at least one locking recess, particularly preferably one countersunk hole for each nozzle and/or each nozzle of a set, wherein at least one position of the offset unit relative to the material feed unit can be determined, preferably releasably, by the at least one locking means. According to a preferred embodiment of the extrusion head, it is provided that at least one stop is provided, wherein the rotation of the offset unit in at least one direction, preferably in two directions, is limited by the at least one stop, preferably in combination with at least one stop guide. The at least one stop can perform a protective function for the lines used and/or against any contamination. In a preferred embodiment, it can be provided that at least one sensor can be provided for detecting the rotational position of the offset unit relative to the material feed unit. In a preferred embodiment variant, it can be provided that the at least one sensor for detecting the rotational position of the offset unit relative to the material feed unit can be an absolute rotary encoder or an incremental rotary encoder and/or a Hall sensor with preferably a magnetic tape and/or an inductive sensor with preferably a magnet wheel and/or an electro-optical sensor with preferably a reticle. In a preferred embodiment, it can be provided that the at least one sensor for detecting the rotational position of the offset unit relative to the material feed unit can be connected or connectable to the offset actuator and/or to the transmission gear and/or to the drive gear. According to a preferred embodiment of the extrusion head, it is provided that the material feed unit and/or the offset unit has a cable feedthrough, in particular an electrical rotary feedthrough and/or a cable screw connection. In a preferred embodiment, it can be provided that the material feed unit and/or the offset unit can have a cable screw connection with preferably a seal and/or a sealing insert and/or an electrical rotary feedthrough designed as a slip ring with preferably a seal. According to a preferred embodiment of the extrusion head, it is provided that a platform is provided, wherein the product can be manufactured on the platform by means of additive manufacturing. In a preferred embodiment, it can be provided that the platform is designed as a rotary table in order to provide an additional (for example fifth) axis of rotation, in particular the C-axis, for 5-axis additive manufacturing, in order to preferably produce complex geometries with undercuts without the use of support structures, wherein the fourth axis, in particular the A-axis or B-axis, is realized by the tiltable extrusion head. According to a preferred embodiment of the extrusion head, it is provided that the extrusion head within a Mounting structure is arranged, wherein a convection guard is provided between the extrusion head and the mounting structure, and/or the mounting structure is arranged within a travel system, wherein a convection guard is provided between the mounting structure and the travel system, preferably at least one travel device of the travel system. The convection guard can be one-piece or multi-piece. Several convection guards that are not directly connected to one another can also be provided, wherein each convection guard can be one-piece or multi-piece in itself. If several convection guards are provided, these can also be referred to collectively as one convection guard. In a preferred embodiment variant, it can be provided that the travel system can have at least one frame and at least one drive in order to move the mounting structure. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is arranged between the extrusion head and the mounting structure in such a way that two areas are present inside and/or outside the mounting structure, in particular within an imaginary infinite volume of the projected base area of the mounting structure, wherein the material feed unit is essentially arranged in one of the two areas and the offset unit is essentially arranged in the other of the two areas, and/or the convection protection is arranged between the mounting structure and the travel system, preferably at least one travel device of the travel system, in such a way that two areas are present within the travel system, wherein the material feed unit is essentially arranged in one of the two areas and the offset unit is essentially arranged in the other of the two areas. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is connected or connectable to the extrusion head and the mounting structure and/or to the mounting structure and the travel system, preferably at least one travel device of the travel system, preferably detachable, non-destructively, by means of one or more convection protection connection devices. According to a preferred embodiment of the extrusion head, it is provided that the convection protection is flexibly deformable due to its shape and/or its material. According to a preferred embodiment of the extrusion head, it is provided that the convection protection has or consists of at least one separating means, preferably a separating hose and/or a separating membrane and/or a bellows, preferably flat, conical, pyramid-like, particularly preferably stepped pyramid-like, and/or a folding roof cover, preferably a multi-part folding roof cover. According to a preferred embodiment of the extrusion head, it is provided that the convection protection, in particular the separating means, consists at least partially of silicate fabric and/or at least partially of aramid fabric, preferably of aluminized preox para-aramid fabric, and/or at least partially of rubber, preferably of fluororubber (FKM) or silicone rubber (HTV), and/or is partially coated with silicone and/or polytetrafluoroethylene. In a preferred embodiment, it can be provided that the convection protection, in particular the folding roof cover, preferably consists of several elements, at least partially of coated plastic fabric, in particular sewn and/or thermally welded and/or glued, and/or at least one metal. According to a preferred embodiment of the extrusion head, it is provided that the convection protection has at least one shaft seal, in particular a radial sealing lip and/or at least one axial sealing lip and/or at least one labyrinth seal, and/or at least one stiffener, in particular in the form of a stiffening ring. In a preferred embodiment, it can be provided that the at least one shaft seal is an integral part of the convection protection or a separate component that can be attached to it. According to a preferred embodiment of the extrusion head, it is provided that at least one measuring device is provided, wherein the at least one measuring device can be a mechanical, thermoelectric, resistive, piezoelectric, capacitive, inductive, optical, acoustic and/or magnetic measuring device. In a preferred embodiment, it can be provided that an arrangement is provided, wherein the arrangement consists of at least the following arrangement components: an extrusion head and a convection protection and a mounting structure, wherein a shield, in particular thermal and essentially tight, is provided by the interconnected arrangement components, wherein the shield, in particular thermal and essentially tight, divides the operating space into two spatial areas, preferably wherein the arrangement additionally has a travel system. In a preferred embodiment, it can be provided that the shield is constructed by a mounting structure, the material feed unit, the offset unit and at least one convection protection between the mounting structure and the extrusion head, in particular the material feed unit. It can preferably be provided that a travel system and a convection protection between the mounting structure and the travel system also build up the shield. In a particularly preferred embodiment, it can be provided that the shield is constructed at least partially by the offset unit receiving block of the material feed unit and by bearings between the material feed unit and the offset unit, in particular roller/sliding bearings with seals, as well as by the cooling block and/or by the sheathing and/or by some of the existing seals and/or cable feedthroughs, preferably cable screw connections and/or electrical rotary feedthroughs designed as a slip ring, of the offset unit. In a preferred embodiment, it can be provided that the offset unit and the separating device can be arranged within the offset unit receiving block, wherein the drive wheel and/or the at least one receiving device and the separating device and/or the at least one blade element can be provided in a recess, which is referred to below as the separating chamber, of the offset unit receiving block, wherein this separating chamber can be closed at the bottom by at least part of the arrangement of the shield and at the top can be at least partially open or closed with the exception of the insertion line. In this way, the convection of the waste heat from the drives from above to the cutting point can be advantageously prevented and/or reduced. Protection is also sought for a method and/or use for producing a product with an extrusion head according to the invention. According to a preferred embodiment of the method, it is provided that by tilting the extrusion head, the nozzle of one of the existing condenser units is moved to a position below the remaining nozzles of the existing condenser units. According to a preferred embodiment of the method, it is provided that by rotating the offset unit in the tilted state of the extrusion head, the nozzle of one of the existing condenser units is moved to a position below the remaining nozzles of the existing condenser units. According to a preferred embodiment of the method, it is provided that the offset unit has at least one set of at least two condenser units, wherein the at least two condenser units of the set have two different nominal widths of the nozzles, and by rotating the offset unit, preferably in the inclined state of the extrusion head, a product is produced with different accuracy based on the nominal widths of the nozzles of the at least two condenser units. According to a preferred embodiment of the method, it is provided that by tilting the extrusion head starting from a vertical starting position in at least two Directions a material change between at least two different extrusion materials takes place. According to a preferred embodiment of the method, it is provided that undercuts are taken into account in a product to be manufactured and the product is built up layer by layer with at least one extrusion material by tilting the extrusion head and/or by rotating the offset unit, wherein during the layer-by-layer construction by tilting the extrusion head and/or by rotating the offset unit, a support structure for supporting the undercuts of the product is additionally built up with at least one other extrusion material. Further details and advantages of the invention are explained in more detail below with reference to the description of the figures with reference to the drawings. Therein show: Fig. 1 to 3: various perspective views of an extrusion head according to the invention; Fig. 4: a front view of the extrusion head from Fig. 1 with a partial section; Fig. 5: a detailed view of a first separating device and a first introduction line based on detail I from Fig. 4; Fig. 6: a sectional view of the first separating device and the first insertion line from Fig. 5 based on the sectional plane B-B from Fig. 5; Fig. 7: a sectional view of a second separating device and a second insertion line based on the sectional plane B-B from Fig. 5; Fig. 8: a sectional view of a third separating device based on the sectional plane B-B from Fig. 5; Fig. 9: a sectional view of a fourth separating device based on the section plane B-B from Fig. 5; Fig. 10: a sectional view of a fifth separating device based on the section plane B-B from Fig. 5; Fig. 11: a perspective view of an inlet line from Fig. 4; Figs. 12 to 21: various design variants of blade elements; Fig. 22: a side view of the extrusion head from Fig. 1 with a first variant of a cooling device, shown as a sectional view based on the section A-A; Fig. 23: a side view of the extrusion head with a second variant of a cooling device, shown as a sectional view; Fig. 24: a side view of the extrusion head with a third variant of a cooling device, shown as a sectional view; Fig. 25: a perspective view of the offset unit from Fig. 1 without condenser units; Fig. 26: a perspective view of the offset unit from Fig. 1 with condenser units; Fig. 27: a detailed view of a nozzle of a condenser unit of an extrusion head based on detail II from Fig. 4; Fig. 28: a front view of the extrusion head from Fig. 1, installed in a mounting structure, shown with a partially cut-out cover of the mounting structure; Fig. 29 to 32: various design variants of closures of a convection protection based on detail III from Fig. 28; Fig. 33 to 35: various positions of the tiltable extrusion head from Fig. 1; Fig. 36: a perspective view of the extrusion head with the mounting structure from Fig. 35, implemented in a travel system. Fig. 37: an arrangement of the extrusion head within the mounting structure and a first platform; Fig. 38: an arrangement of the extrusion head within the mounting structure and a second platform; Fig. 39: an exploded view of the support bracket, the tilt actuator, the tilt shaft and the travel system. Fig. 1 to 3 show various perspective views of an extrusion head 1 according to the invention. In Fig. 1 it can be clearly seen that the extrusion head 1 consists of the material feed unit 2 and the offset unit 6 arranged underneath. The material feed unit 2 is basically used to feed and/or receive at least one extrusion material from a material storage unit and can also contain other functions and components required for this. In this embodiment, two extrusion materials can be fed independently of one another. For this purpose, the extrusion material, which is preferably designed as a filament, is introduced into one of the two material receiving nozzles 33 or 34. As shown in Fig. 1, a first extrusion material can be introduced into the first material receiving nozzle 33 and a second extrusion material into the second receiving nozzle 34. The material receiving nozzles 33 and 34 can be arranged on the top of the extrusion block 35, but other positions are also conceivable. It can also be provided, as shown here, that a separate extrusion actuator 31, 32 is provided for the extrusion materials used. An actuator can in particular be a motor. In this exemplary embodiment, the first extrusion material, which is introduced into the extrusion block 35 through the first material receiving nozzle 33, can be moved via a system arranged in the extrusion block 35 with the aid of the extrusion actuator 31. The first extrusion material can be conveyed from the first material receiving nozzle 33 via the extrusion block 35 and further via the offset unit receiving block 36 to one of the liquefier units 7. The conveying direction can also run in the opposite direction in order to pull the first extrusion material at least partially in the direction of the first material receiving nozzle 33. The same conveying operation as described above can also be carried out with the second extrusion material, which can be introduced into the second material receiving nozzle 34, wherein the second extrusion actuator 32 conveys the second extrusion material within the extrusion block 35 and the offset unit receiving block 36 into one of the condenser units 7 or withdraws it in the opposite direction. The extrusion block 35 can, as shown in Fig. 1, be connected to the two extrusion actuators 31 and 32 and to the offset unit receiving block 36. The offset unit receiving block 36 can in turn be connected to a Offset actuator 30, wherein the offset actuator 30 can serve as a drive for moving the offset unit 6 and preferably has an incremental or absolute rotary encoder. In addition, the offset unit receiving block 36 can be connected to the offset unit 6, wherein the offset unit 6 is movably mounted in the offset unit receiving block 36. As shown here, the offset unit 6 can be mounted so as to be rotatable about the Z axis, wherein such a rotary movement can be caused by the offset actuator 30. In this embodiment, the offset unit 6 has six condenser units 7, wherein only three of them can be seen in Fig. 1. The condenser units 7 can, as shown here, be covered with a casing 37 and/or attached to a casing 37. The other components of the offset unit 6 will be explained in more detail later. The offset unit receiving block 36 can, as shown here, have one or more cooling medium interfaces 60. These can serve as an inlet point and/or outlet point for a cooling medium in order to cool the material feed unit 2. The cooling medium interface 60 can preferably be designed as a push-fit connection. The offset unit receiving block 36 is in contact with an inclination shaft 38, via which the offset unit receiving block 36 can be connected to a support bracket 28 and can be inclined via an inclination actuator 29. The support bracket 28 can in turn be implemented in a travel system in order to move the extrusion head 1 in at least one direction. More details on this will be explained in more detail later. The inclination shaft 38 can, as shown here, be designed such that the extrusion head 1 as a whole with the exception of the support bracket 28 and the tilt actuator 29. In the case shown in Fig. 1, the extrusion head 1 can be rotated relative to the support bracket 28. The tilt actuator 29 can serve as the drive for this movement. The rotational movement of the extrusion head 1 in this case runs around the X-axis. Fig. 2 shows the extrusion head 1 from Fig. 1 from a different perspective view. The offset unit 6 in particular can be seen better. In this illustration, all six condenser units 7 can be seen, which are arranged radially inside the casing 37. As shown in Fig. 2, convection protection connection devices 39 can be provided in order to attach a convection protection to the offset unit receiving block 36. For example, a pleated bag can be connected to the offset unit receiving block 36 via screw connections. Fig. 3 shows the extrusion head 1 from Fig. 1 from a different perspective view. One of the two conveyor devices 16, 40 and a recess for the inclination shaft 38 can be clearly seen. The conveyor devices 16, 40 can contain at least two feed wheels 41, between which the at least one extrusion material can be located. The at least one extrusion material can be moved by rotating the feed wheels 41 of the conveyor device 16, 40. A detailed description follows later. As can already be seen in Fig. 1 and 2, Fig. 3 also shows how the offset unit receiving block 36 has two triangular Side walls 42 can be connected to a rear wall 43, the rear wall 43 having a recess for the inclination shaft 38. In addition, in particular for better absorption of thrust forces, sleeves and/or dowel pins can be provided in opposing recesses between the rear wall 43 and the offset receiving block 36. The inclination shaft 38, not shown in Fig. 3, can connect the rear wall 43 to the support bracket 28, also no longer shown here, and can be actuated by the inclination actuator 29, also no longer shown here, so that the extrusion head can be rotated relative to the support bracket 28. In this case, this rotational movement runs around the X-axis. Furthermore, lines 44 can be provided, which can serve as electrical lines and/or cooling lines for the offset unit 6. For example, the lines 44 can be used as a power supply and/or as a cooling medium supply and/or as signal transmission paths for measuring devices such as temperature sensors. Fig. 4 shows a front view of the extrusion head 1 from Fig. 1 to 3 with a partial section. In this view, the section plane of the partial section runs along the two guide paths of the two extrusion materials, starting at the material feed hoses 45, 46, over the two material intake nozzles 33, 34, the extrusion block 35, the offset unit intake block 36 and the condenser units 7 and ending at the nozzle channels 23. In other words, the section plane lies in the YZ plane at the height of the extrusion material guide. As in the previous Fig. 1 to 3, the side walls 42, which are connected on the one hand to the rear wall 43 and on the other hand to the offset unit intake block 36, can be seen. The Offset unit receiving block 36 is also connected to the extrusion block 35. At least one conveyor device 16, 40 for at least one extrusion material can be located in the extrusion block. In the embodiment shown here, the two conveyor devices 16 and 40 are provided to move two extrusion materials independently of one another. In other embodiments, more or fewer conveyor devices and/or more or fewer extrusion materials can be provided. In the following, the extrusion head is described using a first guide path for a first extrusion material. It should be noted, however, that the second guide path shown here can be described in the same way and the description that applies to the first guide path can generally but not necessarily apply to other guide paths. This means that guide paths for extrusion materials can be provided as in Fig. 4, but are not limited to the embodiment shown. The first guide path begins at the first material feed hose 45, into which the first extrusion material can be introduced. The first material feed hose is connected to the first material intake nozzle 33, which in turn is connected to the extrusion block 35. The first material intake nozzle 33 can preferably be a push-fit connection. The first guide path continues through the extrusion block 35 to the first conveyor device 16, which has two feed wheels 41. The feed wheels 41 can be driven by a first extrusion actuator 31. The rotating feed wheels 41 can either convey the first extrusion material further in the direction of the offset unit 6. or also be conveyed back in the opposite direction. Along the first guide path, an inlet line 14 and a separating device 4 are provided between the feed wheels 41 and the offset unit 6, specifically the drive wheel 47, which will be explained in more detail later. The first guide path passes the offset unit 6, starting through the drive wheel 47, and then through a continuation line 17, in particular a heat break line, in the cooling block 50 of the offset unit 6, whereby the continuation line 17, in particular the heat break line, protrudes beyond the cooling block 50 of the offset unit 6 and reaches into one of the condenser units 7. Directly at the end of the continuation line 17, in particular the heat break line, in one of the condenser units 7, there is a nozzle pipe 52 which directs the first guide path to the nozzle channel 23, where it ends. In a preferred embodiment, as shown in Fig. 4, the extension line 17, in particular the heat break line, can run from the upper end of the cooling block 50 to one of the existing condenser units 7. In this case, the extension line 17 can preferably form a section between the cooling block 50 and the corresponding condenser unit 7 in which the extension line 17, in particular the heat break line, is free-standing. This means that the extension line 17, in particular the heat break line, can be installed partially free-standing or, in other words, partially without contact with other components. This has the advantage that the heat generated by the condenser units 7 can thus migrate more difficultly to the cooling block 50. Apart from the convection of the ambient air, heat can then only be transferred via the thin components such as the extension line 17, in particular the heat break line, preferably made of a material with a low heat transfer coefficient, particularly preferably Stainless steel, migrate to the cooling block 50, whereby a lower heat transfer can be achieved. In a preferred embodiment, it can be provided that a section of the extension line 17, in particular the heat break line, which is partially free-standing or, in other words, partially installed without contact with other components, can be air-cooled, whereby the air cooling can take place without pressure or with compressed air, preferably in an area at least partially separated from the installation space to maintain the thermal homogeneity of the installation space air. Cooling devices 19 can be provided both in the material feed unit 2 and in the offset unit 6. As shown in this embodiment, these cooling devices 19 can be provided specifically in the offset unit receiving block 36, preferably in the heat sink 48, as well as in the cooling block 50 of the offset unit 6. The cooling devices 19 can, as shown in Fig. 4, be holes through which the cooling medium flows. The offset unit 6 can be in contact with bearings 49 with the help of the drive wheel 47 and the cooling block 50 of the offset unit 6, which in turn are in contact with the material feed unit 2, specifically in Fig. 4 with the offset unit receiving block 36. In this way, the offset unit 6 can be rotatably mounted in the material feed unit 2, specifically in the offset unit receiving block 36. Lines 44 can be provided between the two guide paths, wherein the lines 44 can be provided for the supply and removal of cooling media and/or as a power connection. As shown in Fig. 4, the lines 44 can, among other things, Power lines for the condenser units 7 and signal transmission paths for measuring devices 68, in particular temperature sensors. Before the lines 44 are distributed to the individual condenser units, they can be guided through a cable feedthrough 24, in particular a cable screw connection with preferably a seal and/or a sealing insert used as strain relief and/or an electrical rotary feedthrough, for example designed as a slip ring with preferably a seal used as strain relief, torque relief, energy transmission and/or signal transmission. Fig. 5 shows a detailed view of a first separating device 4 and a first introduction line 14 based on the detail I from Fig. 4. The extrusion material 3 can, as already described above, be moved by the feed wheels 41. The extrusion material 3 can be conveyed along the introduction line 14 to the separating device 4. The extrusion material 3 can then be introduced into a receiving device 18, in this specific embodiment designed as a counterbore in the drive wheel 47. After being introduced into the receiving device 18, the extrusion material can be conveyed further so that it is moved by the drive wheel 47 of the offset unit 6 and further through the feed line 17, in particular the heat break line, in the cooling block 50 of the offset unit 6. In the area in which the separating device 4 is provided, the extrusion material 3 can be severed. The feed line 17 can, as shown in Fig. 5, represent a heat break line that is located in the cooling block 50. In another preferred embodiment, It can be provided that the extension line 17 runs completely through the cooling block 50 and the drive wheel 47 of the offset unit 6. If the extension line 17 runs to the upper end of the offset unit 6, specifically to the upper end of the drive wheel 47, the receiving device 18 can be part of the extension line 17. The separating device 4 has at least one blade element 5, wherein the at least one blade element 5 is fastened to the material feed unit 2. At least one blade connecting device 8 can be provided for fastening the at least one blade element 5, wherein the blade connecting device 8 can be, for example, a screw connection between the blade element 5 and the material feed unit 2. One of the two existing blade elements 5 can be clearly seen in Fig. 5. The blade element 5 is a flat and square blade in this embodiment. The blade element 5 is arranged in the material feed unit 2 in such a way that the material feed unit 2 and the offset unit 6 can be guided past each other with almost no gaps. When the offset unit 6 is moved by actuating the drive wheel 47, the extrusion material 3 can be guided to the at least one blade element 5 and severed at a severing point. The upper severed end of the extrusion material 3 can then be introduced into one of the existing receiving devices 18 depending on the movement of the offset unit 6 and thus fed to one of the existing liquefaction units. In order to achieve a clean severing of the extrusion material 3 and/or bending of the extrusion material 3 during of the cutting process, it is advantageous to guide the offset unit 6 past the material feed unit 2 with almost no gaps. It can be clearly seen in Fig. 5 that the introduction line 14 is arranged as a separate component in the material feed unit 2 and has two projections 57. These two projections can be used to guide the extrusion material 3 closer to a cutting edge 11, so that bending of the extrusion material 3 during cutting can be avoided. In the case of an imaginary triangle, the first corner of which is the center of the axis of rotation of the offset unit, the second corner of which is the center of the cross-section of the preferably circular extrusion material 3 above the cutting edge and the third corner of which is the center of the cross-section of the preferably circular extrusion material 3 below the cutting edge, the extrusion material 3 may bend along the cutting edge during the cutting of the extrusion material 3 due to the cutting rotational movement carried out and carried out by the offset unit 6, whereby the adjacent side of the imaginary triangle described above is shortened. As shown here, the insertion line 14 extends into an effective area of the blade element 5, specifically the two projections 57 of the insertion line 14 extend into an effective area of the blade element 5. In other words, the insertion line 14 with the two projections 57 ends in an area between the blade element bottom 55 and the blade element top 56. If the extrusion material 3 bends slightly during the cutting process, the extrusion material 3 can be moved back upwards by the feed wheels 41, whereby the extrusion material 3 can be straightened again in the inlet line 14. Fig. 6 shows a sectional view of the first separating device 4 and the first inlet line 14 from Fig. 5 using the section plane B-B from Fig. 5. In contrast to the detailed view from Fig. 5, the sectional view using the section plane B-B from Fig. 5 shows that the separating device 4 consists of two individual blade elements 5. Both blade elements 5 are flat and square blades. One of the two projections 57 can be clearly seen in the section B-B of Fig. 6. The projection 57 of the inlet line 14 shown here protrudes into an imaginary blade element hollow volume 15 of the separating device 4, whereby the separating device 4 here has two blade elements 5. In this exemplary embodiment, the imaginary blade element hollow volume 15 of the separating device 4 with the two blade elements 5 arranged parallel to one another corresponds to a trapezoidal prism, the trapezoidal cross section of such a trapezoidal prism being visible in Fig. 6. The surface of the projection 57 visible in Fig. 6 also corresponds to a trapezoidal surface, the trapezoidal surface of the projection 57 being smaller than the trapezoidal cross section of the prism which describes the imaginary blade element hollow volume 15 of the separating device 4. The trapezoidal surface of the projection 57 lies between the two blade elements 5 and is delimited by one of the cutting surface upper sides 10 of the blade elements 5. The lower side of the trapezoidal surface of the projection 57 ends in an area between the blade element bottom side 55 and the blade element top side 56. The projections 57 of the introduction line 14 reduce the imaginary blade element hollow volume 15 of the separating device 4, with the two projections 57 limiting the trapezoidal prism on two sides. In other embodiments, more or fewer blade elements 5 can also be provided. The number and shape of blade elements 5 shown here are not to be understood as limiting. Fig. 7 shows a sectional view of a second separating device 4 and a second introduction line 14 based on the section plane B-B from Fig. 5. In contrast to the embodiment from Fig. 6, in Fig. 7 the introduction line 14 is not provided as a separate component, but as a continuous guide bore through the extrusion block 35. The projections 57, only one of which can be seen in Fig. 7, are also components of the extrusion block 35. The shape and arrangement of the projections 57 correspond to the shape and arrangement from Fig. 6. Here too, the projections 57 protrude into an imaginary blade element hollow volume 15 of the separating device 4 and delimit it. In contrast to Fig. 6, only one blade element 5 is provided here, which is flat and has a round cutting edge 11. The imaginary blade element hollow volume 15 of the separating device 4 thus corresponds to a truncated cone in this embodiment. For a better illustration of this imaginary blade element hollow volume 15, specifically the truncated cone, reference is made to Figs. 16 to 18. Fig. 8 shows a sectional view of a third separating device 4 based on the section plane B-B from Fig. 5; Unlike in Fig. 7, in Fig. 8 the transverse groove of the projections 57 extends upwards like a funnel, resulting in a guide recess 58 and the funnel extending like an elongated hole. tapered to the round through hole. This leads to more freedom of movement of the extrusion material 3 to the cutting edge, whereby the blade element 5 can better penetrate into the extrusion material 3. In a preferred embodiment, it can also be provided that the receiving device 18 can be designed as a separate component within the drive wheel 47 of the offset unit 6. It can be provided that the receiving device 18 can be formed as a flat plate, as a flat ring or as a sleeve with preferably a countersunk hole. Fig. 9 shows a sectional view of a fourth separating device 4 based on the section plane B-B from Fig. 5. The separating device 4 can, as shown in Fig. 9, have only one blade element 5, whereby the blade element can be a blade sleeve. In this embodiment, the introduction line 14 is not a separate component, but is provided as a guide hole in the extrusion block 35. It can also be provided that the through-opening of the blade sleeve is designed in the form of an elongated hole or, as described in Fig. 8, the projections 57 are formed by a component inserted separately in the blade sleeve. Fig. 10 shows a sectional view of a fifth separating device 4 based on the section plane B-B from Fig. 5; Unlike in Fig. 9, in this view the continuation line 17 is designed in such a way that it passes through both the cooling block 50 and the drive wheel 47 to the upper end. of the offset unit 6 and thus simultaneously takes over the function of the receiving device 18. Fig. 11 shows a perspective view of the insertion line 14 from Fig. 4 to 6. The insertion line 14 is a substantially cylindrical component, as shown here, shaft-shaped, with a central through-hole through which the extrusion material 3 can be guided. The insertion line 14 has a collar with which the insertion line can be arranged in the extrusion block 35. Furthermore, the insertion line 14 preferably has a flat milled section or, for example, a toothed profile on the collar with which the orientation of the projections 57 can be aligned with the blade element 5. At one end of the insertion line 14 are the two projections 57, which together form a guide recess 58, in this specific case a groove. With the help of the projections 57, the extrusion material 3 can be guided closer to the cutting edges 11 of the blade elements 5. More details about this were explained in more detail in Fig. 5 to 7. Fig. 12 to 21 show various design variants of blade elements 5. Fig. 12 shows a perspective view from above of one of the blade elements 5 from Fig. 4 to 6. On one side, the blade element 5 has a cutting edge 11. Between the blade element top 56 and the cutting edge 11, a cutting surface top 10 is provided, which is inclined relative to the blade element top 56. When the blade element 5 is attached to or in the material feed unit 2, the cutting surface top 10 is arranged facing away from the offset unit 6. The cutting surface top 10 facing away from the offset unit 6 has two surface sections, the first cutting surface section 12 adjoining the cutting edge 11 and the second cutting surface section 13 not adjoining the cutting edge 11. As shown in Fig. 12, it can be provided that the first cutting surface section 12 has a different, in particular a larger, angle with the cutting surface bottom 9 of the at least one blade element 5 facing the offset unit 6 than the second cutting surface section 13 encloses. On the blade element top side 56 of the blade element 5, two parts of a blade connection device 8 can be seen, whereby the blade connection device 8 can be a screw connection, preferably by means of countersunk screws, between the material feed unit 2 and the blade element 5. Fig. 13 shows a perspective view from below of the blade element 5 from Fig. 12 with the additional blade connection devices 8, which are designed here as countersunk screws. On the blade element bottom side 55, it can be partially seen that countersunk holes are provided, which can be connected to the material feed unit 2 with the blade connection devices 8, as shown here two countersunk screws. Fig. 14 shows a perspective view from above of a four-edged blade element 5. This embodiment of a blade element 5 has a square and flat base body, but in contrast to the already described Four cutting edges 11 are provided for blade elements 5. The number of cutting edges 11 shown here is not to be understood as limiting. Any number of cutting edges can be provided per blade element 5 to the desired extent. More than one cutting edge per blade element 5 can have the advantage that a blade element 5 can easily be used several times as a result of wear and/or damage to a cutting edge 11. To do this, the blade connection device 8 only has to be loosened, the blade element re-equipped with a new cutting edge 11 and the blade connection device 8 re-attached. Fig. 15 shows a perspective view from below of the blade element 5 from Fig. 14. What has already been said about the blade connection device 8 also applies here. Fig. 16 shows a perspective view from above of a flat and square blade element 5 with a round cutting edge 11. As already explained, this embodiment of a blade element 5 forms a truncated cone as an imaginary blade element hollow volume 15. What has already been said about the blade connection device 8 also applies here. Fig. 17 shows a perspective view from below of the blade element 5 from Fig. 16. What has already been said about the round cutting edge 11 and the blade connection device 8 also applies here. Fig. 18 shows a perspective view from above of a flat and round blade element 5 with a round cutting edge 11. The round blade element 5 is circular in shape and shown as a sectional view. The section runs centrally through the axis of rotation of the circular ring. As already explained As explained, this embodiment of a blade element 5 forms a truncated cone as an imaginary hollow volume 15 of the blade element. In this embodiment, the blade connection device 8 can be designed as a positive and/or non-positive connection, preferably as a press connection, and can be connected or connected to the material feed unit 2. Fig. 19 shows a perspective view from above of a round blade element 5 with a round cutting edge 11. The round blade element 5 is sleeve-shaped here and shown as a sectional view. The section runs centrally through the axis of rotation of the sleeve. In this embodiment, the blade connection device 8 can be designed as a positive and/or non-positive connection, preferably as a press connection, and can be connected or connected to the material feed unit 2. Fig. 20 shows a perspective view from above of a round blade element 5 with a round cutting edge 11. The round blade element 5 is sleeve-shaped here and shown as a sectional view. The section runs centrally through the axis of rotation of the sleeve. In the embodiment in Fig. 20, the sleeve-shaped blade element 5 has part of a blade connecting device 8, the part of the blade connecting device 8 being designed here as an external thread. Fig. 21 shows a perspective view from above of a block-like blade element 5. The block-like blade element 5 has a round, for example elliptical, cutting edge 11, the hole formed thereby representing the tapered end of a wedge-shaped through-opening through the blade element 5. On the blade top 56, the upper end of the wedge-shaped through-opening corresponds to an elongated hole. Next to the elongated hole, there are further through-openings on both sides, which have countersunk holes on the blade bottom 55 in order to be able to accommodate countersunk head screws as in Figure 13 and thus connect the blade element 5 to the material feed unit 2. In a preferred embodiment, shown in Figures 12 to 21, the cutting surface bottom 9 can be substantially congruent with the blade element bottom 55. Figure 22 shows a side view of the extrusion head 1 from Figure 1 with a first variant of a cooling device 19, shown as a sectional view based on section A-A. The sectional view A-A in Fig. 22 shows the extrusion head 1 with a cutting plane which lies in the plane XZ and runs through the axis of rotation 69 from Fig. 4. In other words, the cutting plane runs along the plane XZ and centrally through the extrusion head 1; exactly between the two material receiving nozzles 33 and 34 from Fig. 4. As already described in Fig. 4, the sectional view in Fig. 22 shows the extrusion head 1 with its individual parts, whereby the following parts can be seen in the material feed unit 2: the extrusion block 35, the offset unit receiving block 36, which in turn comprises the cooling body 48 and the cooling device 19, the offset actuator 30, one of the visible beveled side walls 42, the rear wall 43 with a recess for the inclination shaft 38 and the Cooling medium interfaces 60. In addition, in this view, in contrast to Fig. 4, it can be seen that at least one locking means 26 and a transmission gear 63 are also provided in the material feed unit 2. Drives for moving components of the excursion head 1 can, as known from the prior art, be chain drives, belt drives, swivel mechanisms made of cylinders with racks and gears or other drives. The locking means 26 releasably locks the offset unit 6, which is movable relative to the material feed unit 2. For this purpose, the at least one locking means 26 can determine positions of the offset unit 6, whereby an exact position of the condenser units 7 can be achieved. In other words, this means that intermediate positions or end positions of the offset unit 6 can be determined by the at least one locking means 26. This advantageously makes it possible to dispense with additional braking devices in or on the drive, in particular in or on the offset actuator 30. In a preferred embodiment, the at least one locking means 26 can be operated mechanically and/or electromechanically and/or pneumatically and/or hydraulically and/or electromagnetically. In a preferred embodiment, as shown in Fig. 22, the at least one locking means 26 can be a spring-loaded pressure piece, preferably a spring-loaded ball pressure piece. The transmission gear 63 transmits a movement from the offset actuator 30 to the drive gear 47 of the offset unit 6. That is, by The offset unit 6 can be driven by the power transmission of the offset actuator 30 via the transmission gear 63. It should be noted that the offset unit 6 can also be driven by alternative power transmission means such as chain drives or belt drives or cable drives or coupling rods and/or alternative drive forms such as an electromechanical and/or pneumatic and/or hydraulic cylinder swivel mechanism. In addition to the transmission gear 63, the offset unit 6 is connected to the material feed unit 2 via the bearings 49, which can be designed as roller bearings as shown here but are not necessarily required, and is thus rotatably mounted. The offset unit 6 comprises several components, of which the following can be seen as already in Fig. 4: the drive wheel 47, the cooling block 50 including the cooling device 19, the casing 37, the condenser units 7. In contrast to Fig. 4, the following components can also be seen here: at least one stop 27, at least one centering means 62 and two further cooling medium interfaces 60. The stop 27 can, as shown here, be a bolt-shaped stop, wherein the stop can be fastened in or on the drive wheel 47 and can be guided in a stop guide 70 in the material feed unit 2 that runs radially around the axis of rotation 69 of the offset unit 6. The stop guide 70 can be designed such that the stop guide 70 does not form a self-contained guide, but has a component blocking the stop 27 or two blocking ends. In this way, it can be provided that the offset unit 6 can only be moved to a certain extent relative to the material feed unit 2. In concrete terms, it can be provided as an embodiment that the stop 27 can only be guided 120 ° within the stop guide 70 running radially around the axis of rotation 69 before the stop 27 and thus the offset unit 6 are blocked. This can be particularly advantageous if, as can be clearly seen in Fig. 2, six condenser units 7 are provided in the offset unit. In this case, for example, three condenser units 7 arranged one after the other can represent a first set 21 and the remaining three condenser units 7 arranged one after the other can represent a second set 22. The first set of condenser units 7 can be provided for a first extrusion material, wherein preferably each of the three condenser units 7 of the first set 21 is equipped with a different nozzle nominal width for different pressure accuracies. The same applies to the second set 22 for a second extrusion material 3. In order to avoid contamination with different extrusion materials 3 within the individual condenser units 7, the stop 27 within the stop guide 70 can be used so that an inlet line 14 with a first extrusion material 3 exclusively supplies the first set 21 and a second inlet line 14 with a second extrusion material 3 exclusively supplies the second set 22. Of course, embodiments are not limited to two extrusion materials 3 and/or two sets 21, 22 and/or six condenser units 7, but can also have more or fewer extrusion materials 3 and/or sets 21, 22 and/or condenser units 7. In a preferred embodiment, the limitation of the angle of rotation of the offset unit 6 relative to the material feed unit 2 by the stop 27 can also serve as a protective function in that the stop 27 prevents the lines 44 from being torn off, for example by over-rotating the offset unit 6 due to a possible electrical malfunction of the offset actuator 30 or by the extrusion head 1 hitting an object printed in the construction space or the like. In a preferred embodiment, the stop 27 can be used to move to the end positions in an incremental position measuring system for referencing the offset unit 6. In a preferred embodiment, the stop 27 can be used in conjunction with the locking means 26 as a precise and above all cost-effective positioning means, particularly in the end positions. After the stop 27 hits the component or ends blocking the stop within the stop guide 70, the offset unit 6 can be aligned and locked relative to the material feed unit 2 by engaging the locking means 26, preferably a spring-loaded ball pressure piece, in provided locking recesses 54, preferably countersunk holes, after the offset actuator 30 has been switched off. The centering means 62 serves to center the drive wheel 47 relative to the rest of the offset unit 6. As shown here, the centering means 62 can be a dowel pin. In addition to a cooling medium interface 60 in the material feed unit 2, two further cooling medium interfaces 60 in the offset unit 6 can be seen in Fig. 22. One of the two visible cooling medium interfaces 60 in the material feed unit 2 can serve as a supply line and/or return line for a cooling medium in order to cool the material feed unit 2 with the aid of the cooling device 19 in the material feed unit 2, specifically in the cooling body 48. The two cooling medium interfaces 60 in the offset unit 6 can serve as an inlet point and/or outlet point for a cooling medium in order to to cool the offset unit 6 with the aid of the cooling device 19 in the offset unit 6, specifically in the cooling block 50. The cooling medium interfaces 60 of the offset unit 6 can preferably be designed as push-fit connections. In a preferred embodiment, all or individual cooling medium interfaces 60 can be provided on one or more inner walls of the offset unit 6, preferably in the inner cylindrical hollow volume of the cooling block 50. As shown in Fig. 22, the lines 44 run from above through the extrusion block 35, the offset unit receiving block 36 of the material feed unit 2 and further through the cooling block 50 of the offset unit 6, where the lines 44 split. In a preferred embodiment, the lines 44 can run essentially along the axis of rotation 69. Some of the lines 44 represent cooling lines that contain a cooling medium and can guide and/or drain the cooling medium, preferably under pressure, to the cooling medium interfaces 60 of the offset unit 6. Some of the lines 44 represent cables that run through the cooling block 50 of the offset unit 6, passing through a cable duct 24 and can lead to the individual condenser units 7. The lines 44, which lead as cables to the condenser units 7, can fulfill several functions. For example, as shown in Fig. 22, on the one hand each condenser unit can be supplied with energy, preferably electrical, in order to provide the heating power required to soften and/or melt the at least one extrusion material. On the other hand, some of the lines 44 can be used to connect at least one measuring device 68, Preferably, one measuring device 68 is wired to each condenser unit 7 in order to transmit measuring signals through the wiring. In a preferred embodiment, the at least one measuring device 68 can be a temperature sensor that measures the temperature, preferably inside, of one of the existing condenser units 7. The number, position and function of the measuring devices 68 can be freely selected. For example, a measured value can be measured at all points on the extrusion head 1 and/or several measuring devices 68 can be arranged on the same component, preferably on one of the existing condenser units 7. In addition to temperature sensors or instead of them, other measuring devices 68 can be provided, such as pressure sensors or position sensors. The number, position and function of the at least one measuring device is therefore not limited to the embodiments shown. The cooling medium interfaces 60 in the material feed unit 2 and in the offset unit 6 serve, as explained in more detail above, to supply the extrusion head 1 with a cooling medium. It can be provided that, as shown in Fig. 22, the cooling devices 19 in the material feed unit 2 and in the offset unit 6 are arranged as bores within the extrusion head 1. The cooling medium can be guided through the extrusion head 1 through such bores and cool it. In the case of the material feed unit 2, as shown here, a cooling device 19 can consist of several bores that are arranged at the height of the bearings 49 and thus cool both the material feed unit 2, in particular the cooling body 48 of the material feed unit 2, and the bearings 49. In this way The at least one cooling device 19 in the material feed unit 2 can serve to cool the at least one offset unit 6 and/or the at least one extrusion material 3 and/or the separating device 4 and/or the at least one blade element 5 and/or the at least one conveying device 16, 40 and/or the at least one extrusion actuator 31, 32 and/or the offset actuator 30 and/or the bearings 49 and/or the seals and/or the convection protection 25. In the case of the offset unit 6, as shown here, a cooling device 19 can be provided which consists of several bores and is arranged in the cooling block 50 of the offset unit 6. In this way, the at least one cooling device 19 in the offset unit 6 can serve to cool the bearings 49 and/or the at least one extrusion material 3 and/or indirectly via the drive wheel 47 to cool the separating device 4 and/or the at least one blade element 5. As shown in Fig. 22, all cooling devices 19 can be arranged below the drive wheel. This arrangement offers the advantage that heating of the at least one extrusion material 3 and/or the separating device 4 and/or the blade element 5 and/or the at least one conveyor device 16, 40 and/or the at least one extrusion actuator 31, 32 and/or the offset actuator 30 and/or softening of the at least one extrusion material 3, for example due to the heat rising from the condenser units 7 or the rising heat of the heated installation space can be avoided. Preferably, it can be provided that the at least one cooling device 19 is arranged in the area after, preferably directly after, the severing point of the at least one extrusion material 3. It is also conceivable that the at least one cooling device 19 can be arranged at all possible locations inside and/or outside the extrusion head 1, as long as the at least one cooling device 19 is a component of the extrusion head 1 or is connected to the extrusion head 1. The embodiments shown are therefore not to be understood as limiting in relation to the number, position and/or cooling medium used of the cooling devices 19 shown and described here. In a preferred embodiment, it can be provided that either one type of cooling medium such as water or more than one type of cooling medium such as water and a cooling emulsion is used. Fig. 23 shows a side view of the extrusion head 1 with a second variant of a cooling device 19, shown as a sectional view. The extrusion head 1 in Fig. 23 is very similar to that in Fig. 22, whereby a second embodiment of a cooling device 19 is provided in the offset unit 6. Unless otherwise stated in the following description of the figures and/or in Fig. 23, what has already been said about the extrusion head 1 in Fig. 22 also applies to the extrusion head 1 in Fig. 23. In a preferred embodiment, as shown in Fig. 23, the cooling medium interfaces 60 can be arranged partially or completely on the top of the offset unit receiving block 36. The cooling device 19 can have holes in the cooling block 50, radially circumferential grooves on the circumference of a distributor 65 and axial holes within the distributor 65 as well as preferably have one or more push-fit connections for supplying or discharging the cooling medium. Bores within the distributor 65 can connect the cooling medium interfaces 60 of the distributor 65 to the radially encircling grooves of the distributor 65. There can also be a fluid connection between the radially encircling grooves and the bores in the cooling block 50. The distributor 65 can preferably consist of and/or have a substantially cylindrical component, as shown in Fig. 23, wherein a collar can preferably be provided at the upper end in order to be inserted within the offset unit receiving block 36 and held there. The distributor 65 can have a cable feedthrough 24 at the lower end, wherein this cable feedthrough can preferably be designed as a slip ring with at least one seal. In this way, electrical lines can be looped through the distributor 65 in order to supply the condenser units 7 with energy. As is generally known, cooling bores, i.e. bores of the existing cooling devices 19, are limited to the outside with closure means 72. Such a closure means 72 can be seen very clearly in Fig. 23 and can be used for all embodiments mentioned here if necessary. The closure means 72 can preferably be a sealing screw plug. In order to seal the fluid connections between the radial grooves of the distributor 65 and the bores in the cooling block 50, the fluid connections can be arranged by seals above, below and/or between the fluid connections. Fig. 24 shows a side view of the extrusion head 1 with a third variant of a cooling device 19, shown as a sectional view. The extrusion head 1 in Fig. 24 is very similar to that in Fig. 23, whereby a third embodiment variant of a cooling device 19 is provided in the offset unit 6. Unless otherwise stated in the following figure description and/or in Fig. 24, what has already been said about the extrusion head 1 in Fig. 23 also applies to the extrusion head 1 in Fig. 24. In a preferred embodiment, as shown in Fig. 24, two coolant interfaces 60 can be provided, whereby the coolant interfaces 60 can be arranged on the top of the offset unit receiving block 36, whereby in Fig. 24 only one of the two coolant interfaces 60, which are preferably arranged symmetrically around the plane XZ of the extrusion head 1, can be seen. These coolant interfaces 60 can supply the cooling device 19 in the offset unit receiving block 36 with coolant, whereby the cooling circuit can run both through the offset unit receiving block 36 of the material feed unit 2 and through the cooling block 50 of the offset unit 6. In order to realize a self-contained cooling circuit including the material feed unit 2 and the offset unit 6, holes in the offset unit receiving block 36, holes in the cooling block 50 and radially encircling grooves in the cooling block 50 can be provided. The coolant flows from the first of the two coolant interfaces 60 through the holes in the offset unit receiving block 36 until the coolant is then guided through corresponding holes into a radially encircling groove in the body 50 of the offset unit 6. The further course of the cooling circuit can be determined by holes within the cooling block.50 and are guided via a second radially circumferential groove of the cooling block 50 back into the offset unit receiving block 36 to end in the second of the two coolant interfaces 60. In such a preferred embodiment, it can be provided that the two bearings 49 are arranged at a distance from one another and the cooling device 19 is arranged at least partially between these two bearings 49. Preferred embodiments of the extrusion head 1, as shown in Fig. 23 and/or Fig. 24, advantageously enable endless rotation of the offset unit 6 without causing failure of the lines 44, for example due to the lines 44 tearing off. Fig. 25 shows a perspective view of the offset unit 6 from Fig. 1 without condenser units 7. As is known from the previous Fig. 4 and 22 to 24, the offset unit 6 can have the drive wheel 47, the cooling block 50, the casing 37, a stop 27 and the six condenser units 7, whereby the condenser units 7 have been neglected in Fig. 25 for reasons of clarity. In this view, one of the closure means 72 for closing the holes of the cooling device 19 in the offset unit 6 can be clearly seen. Due to the hexagonal shape of the cooling block 50, viewed from top to bottom, the cooling device 19 has six holes, preferably six blind holes, with at least six closure means 72. One of the two cooling medium interfaces 60, through which the cooling medium can be supplied or discharged, can also be clearly seen. On the top of the drive wheel 47 there are several recesses, including a stop recess 51 with a stop 27 located therein and two of four recesses provided for a detachable connection, preferably a screw connection, between the drive wheel 47 and the cooling block 50. The stop recess 51 can perform a protective function in conjunction with the stop 27. In the case of at least two extrusion materials 3, for example a building material and a support material, at least two guide paths, as described in Fig. 4, and several, for example six, condenser units 7, wherein a first set 21 of the condenser units 7 contains an extrusion material 3 for building a product, specifically the building material, and a second set 22 of the condenser units 7 contains another extrusion material 3 for building a support structure for the product, specifically the support material, it may be useful for a stop 27 to be provided. This stop 27 can be inserted into the stop recess 51 and, in combination with the stop guide 70, see Fig. 22, prevents the offset unit 6 from being over-rotated. In this way, it can be ensured that the first set 21 of the condenser units 7 can be supplied exclusively with the extrusion material 3 for building a product, specifically the building material, and the second set 22 of the condenser units 7 can be supplied exclusively with the extrusion material 3 for building a support structure for the product, specifically the support material. Since one stop 27 can be inserted in the stop recess 51 and the stop guide 70 preferably has two end positions, The circular offset movement of the offset unit 6 can be limited both when rotating clockwise and when rotating anti-clockwise and thus secured against over-rotation. Fig. 26 shows a perspective view of the offset unit 6 from Fig. 1 with condenser units 7. In Fig. 26, the opposite half of the offset unit 6 of the section shown can be seen in comparison to Fig. 25. The condenser units 7 are also shown, with the condenser units 7 being fastened to the casing 37 by fastening means. Washers 53 made of materials with low heat transfer coefficients, preferably made of stainless steel or ceramic, in particular zirconium oxide ceramic, can be provided between the condenser units 7 and the casing 37 in the fastening means. What has already been said about Fig. 25 applies accordingly to Fig. 26. Fig. 26 shows the locking recesses 54 and the at least one centering means 62 located on the top of the drive wheel 47 of the offset unit 6. The locking recesses 54 can serve to ensure that the locking means 26 of the material feed unit 2 engages in one of the locking recesses 54 and thus the position of one of the existing condenser units 7 and its line, in particular its receiving device 18 and/or further line 17, can be precisely locked in relation to the material feed unit 2 by the offset unit 6. The locking recesses 54 can be designed as countersunk holes, for example. The number, shapes and positions of the stop recesses 52, the stop 27 and the Stop guide 70 and/or the locking recesses 54 and the locking means 26 are not limited to the embodiments shown. Fig. 27 shows a detailed view of a nozzle of a condenser unit of an extrusion head based on detail II from Fig. 4. In a preferred embodiment, as shown in Fig. 27, the nozzles 77 arranged in and/or on the condenser units 7 can have a nozzle tip 78, the lower end of which comprises a nozzle channel 23, wherein the nozzle tip 78 is surrounded by a nozzle tip shield 59. The nozzle tip shield 59 can serve to mechanically protect the condenser units 7 and/or to contain the heat radiation emanating from the condenser units 7 towards the printed object. Furthermore, the nozzle 77 can have a nozzle tube 52, wherein the nozzle tube 52 contains the extrusion material 3, which the nozzle tube 52 receives from the feed line 17 and discharges through the nozzle channel 23. To heat the extrusion material 3 in the nozzle tube 52, a heating block 61, preferably a two-part heating block 61, is provided around the nozzle tube 52. Between the nozzle tip 78 and the heating block 61, a receiving element 64, preferably a dowel pin or a dowel screw, can be provided on or in the heating block 61. Furthermore, the nozzle tip 78 can have a radially offset groove 79, which is preferably perpendicular to the axis of rotation of the nozzle tube 52 and tangential to the circumference of the nozzle tip. By means of the receiving element 64 and a nozzle groove 79 formed in the nozzle tip 78, the nozzle 77 can preferably be detachably connected or connectable in a form-fitting manner in and/or on the heating block 61 of one of the condenser units 7. In a preferred embodiment, it can be provided that the nozzle tube 52 and/or the nozzle tip 78 is connected or can be connected in a materially bonded, positively bonded and/or non-positively bonded, in particular frictionally bonded, manner to the heating block 61, preferably by a detachable clamping connection of the divided halves of the heating blocks 61 by a screw connection. In a preferred embodiment, a combination of a previously mentioned connection by means of a receiving element 64 with a nozzle groove 79 formed in a nozzle tip 78 and a non-positively bonded, in particular frictionally bonded, connection between the nozzle tube 52 and/or nozzle tip 78 and the heating block 61 can be provided. The embodiments of the attachment of the nozzles 77 in and/or on the condenser units 7 are not limited to the embodiments shown in Fig. 27 and described above. In a preferred embodiment, the nozzle channel 23 can be inclined relative to a longitudinal direction 67. This can have the advantage that when the offset unit 6 and/or the extrusion head 1 is inclined, preferably in relation to the axis of rotation 69 of the extrusion head 1, contact-free printing of the at least one extrusion material 3 can be ensured, wherein during the travel movement of the extrusion head 1, the other liquefaction units 7 do not run the risk of touching the already printed product and/or the previously printed layer due to the inclination of the offset unit 6 and/or the extrusion head 1. Preferably, the nozzle channel 23 can be inclined relative to a longitudinal extension direction 67 such that after inclining the offset unit 6 and/or the extrusion head 1, the nozzle channel 23 of the condenser unit 7 used for extruding an extrusion material 3 is aligned perpendicular to the platform 86. in order to be able to lay down further webs from the previously produced webs of a layer in the same printing layer without restriction. In another preferred embodiment, it can be provided that the existing condenser units 7 can be inclined towards each other in relation to the longitudinal extension direction 67. In addition, the imaginary axes of rotation of the nozzle pipes 52 can preferably intersect at a common point on the axis of rotation 69 of the offset unit 6, preferably above the outlet of the nozzle channel 23, in particular at the level of the imaginary axis of rotation of the inclination shaft 38. Fig. 28 shows a front view of the extrusion head 1 from Fig. 1, installed in a mounting structure 66, shown with a partially cut front panel 75 of the mounting structure. In this illustration, it can be seen that the extrusion head 1 is surrounded by a mounting structure 66. The support bracket 28 of the extrusion head 1 carries the mounting structure 66, wherein the extrusion head 1 and the mounting structure 66 can be moved in at least one direction, preferably in several directions, preferably in two, particularly preferably in three directions, via the support bracket 28. In a further preferred embodiment, it can be provided that the mounting structure 66 carries the support bracket 28 of the extrusion head 1, wherein the extrusion head 1 can be moved in at least one direction, preferably in several directions, preferably in two, particularly preferably in three directions, via the mounting structure 66. The mounting structure 66 in Fig. 28 has a rear panel 73, two side panels 74 and a front panel 75. The mounting structure 66 can be attached to the support bracket 28 via the rear panel 73. In this installed state, the extrusion head 1 is surrounded by the rear panel 73, the two side panels 74 and the front panel 75. In the lower right area of the illustration in Fig. 28, the front panel 75 is shown cut off in the right area. In this way, the cooling block 50 of the offset unit 6 located behind it can be clearly seen. The offset unit receiving block 36 is arranged above the cooling block 50 of the offset unit 6. A convection protection 25 can be seen between the extrusion head 1, specifically the material feed unit 2, even more specifically the offset unit receiving block 36, and the mounting structure 66, specifically one of the two side panels 74. The convection protection 25 is attached to the extrusion head 1 and the mounting structure 66 with a convection protection connection device 39. The convection protection allows the space inside and/or outside the mounting structure 66 or in relation to the extrusion head 1 to be divided into a construction space and a drive space. The construction space is the space in which the extrusion material 3 leaves the extrusion head through the nozzles 77 of the condenser units 7. The drive space is the space that is separated from the pressure space by the convection protection. The convection protection 25 can, as indicated in Fig. 28, connect the rear panel 73, the two side panels 74 and the front panel 75 of the mounting structure 66 to the extrusion head 1, wherein the convection protection can be arranged in such a way that within the mounting structure 66 there is a space below the convection protection 25, in which the offset unit 6 can be arranged, and a another space above the convection protection 25, in which the material feed unit 2 can be arranged. The separation of the space below the convection protection 25, in particular the installation space, and the other space above the convection protection 25, in particular the drive space, can serve to prevent the ambient air warmed up in the space below the convection protection 25 by a heater, preferably by a fan heater, from flowing upwards within the mounting structure 66 and thus heating the extrusion material 3 and/or the material feed unit 2, in particular the separating device 4 and/or the at least one blade element 5 and/or the at least one conveyor device 16, 40 and/or the at least one extrusion actuator 31, 32 and/or the offset actuator 30. The convection protection 25 can be flexibly deformable due to its shape and/or due to the material from which the convection protection 25 is at least partially made. In this way, it is possible to compensate for relative movements between the extrusion head 1 and the mounting structure 66 and at the same time to avoid an exchange of the ambient air above and below the convection protection 25 and furthermore to ensure, for example, the homogeneity of the heated installation space air. This compensation of relative movements is particularly preferred when the extrusion head 1 is designed to be tiltable. The convection protection 25 can be designed as a bellows, as shown in Fig. 28. The convection protection 25 can consist of any material, preferably at least partially of silicate fabric and/or at least partially of aramid fabric, preferably of aluminized preox-para-aramid fabric, and/or at least partially of rubber, preferably of fluororubber (FKM) or silicone rubber (HTV), and/or coated with any material, preferably partially with silicone and/or polytetrafluoroethylene. The extrusion head 1 shown in Fig. 28, installed in the mounting structure 66, together with the convection protection 25, represents an arrangement. In this exemplary embodiment, this arrangement consists of the following arrangement components: the extrusion head 1 and the convection protection 25 and the mounting structure 66, wherein a shield, in particular a tight and thermal shield, can be provided by the interconnected arrangement components, as shown in Fig. 28. In a preferred embodiment, as shown, it can be provided that the shield is constructed by the mounting structure 66, the material feed unit 2, the offset unit 6 and the convection protection 25 between the mounting structure 66 and the extrusion head 1, in particular the material feed unit 2. In a particularly preferred embodiment, it can be provided that the shielding is constructed at least partially by the offset unit receiving block 36 of the material feed unit 2 and by bearings 49 between the material feed unit 2 and the offset unit 6, in particular roller bearings and/or plain bearings with or without their own seals such as radial shaft seals, axial shaft seals, mechanical seals, grooved rings, O-rings or bearing foils, as well as by the cooling block 50 and/or by the casing 37 and/or by some of the existing seals, in particular O-rings, and/or cable feedthroughs 24, preferably cable screw connections and/or electrical rotary feedthroughs designed as slip rings, of the offset unit 6. If the convection protection has a shaft seal 81, as shown in Figs. 29 to 32, one or more seals in the form of separate components can be replaced and/or the need for high-temperature-resistant components above the shield can be avoided. By shielding the arrangement, the operating space in which the arrangement is located and used to manufacture a product can be divided into two areas, with the operating space being divided into an upper drive space and a lower construction space, as shown here. An increased temperature can prevail in the lower construction space due to the processing temperature of the extrusion material 3. The shield prevents and/or reduces heat exchange, in particular due to convection of the ambient air, from the lower construction space to the upper drive space. In this way, the arrangement can shield the separating device 4 from the area below the shield, the construction space. As shown in Fig. 4, 22 to 24, the offset unit 6 is arranged within the offset unit receiving block 36, wherein the drive wheel 47 is provided in a recess, which is referred to below as a separation chamber, of the offset unit receiving block 36. This separation chamber of the offset unit receiving block 36 can be at least partially open at the top or closed or encapsulated with the exception of the introduction line 14. The severing point of the extrusion material 3 can be designed as part of the separation chamber or as an additional separation chamber, whereby the area above the severing point can be separated so that the convection of the waste heat from the drives can be prevented and/or reduced from above. Fig. 29 to 32 show different design variants of closures of a convection protection 25 based on detail III from Fig. 28. In Fig. 29, the detailed view III from Fig. 28 can be seen. It can be seen that the convection protection 25 is connected to the offset receiving block 36 with the aid of a convection protection connection device 39, shown here as a screw connection. The upper end of the cooling block 50 of the offset unit 6 can be seen below the closure of the convection protection 25 attached to the offset receiving block 36. In addition, that area of the convection protection 25 which is connected to the offset receiving block 36 via the convection protection connection device 39 is reinforced by a stiffener 80, in particular a stiffening ring. Fig. 30 shows another embodiment of the convection protection 25 from the detailed view III of Fig. 28. In addition to what has already been said about Fig. 29, the convection protection 25 has an extended end. This extended end includes, on the one hand, a stiffener 80 which is longer and curved than in Fig. 29 and, on the other hand, a shaft seal 81, shown here in the form of a labyrinth seal 82. The labyrinth seal 82 comprises two parts with contours that correspond to one another, one part of the labyrinth seal 82 being in contact with the cooling block 50 and the other part of the labyrinth seal 82 and the other part of the labyrinth seal 82 being part of the base body of the convection protection 25. Fig. 31 shows another embodiment of the convection protection 25 from the detailed view III of Fig. 28. In addition to what has already been said about Fig. 29, the convection protection 25 has an extended end. This extended degree includes, on the one hand, a stiffener 80 that is longer than in Fig. 29 and, on the other hand, a shaft seal 81, shown here in the form of a radial sealing lip 83. The radial sealing lip 83 is in contact with the cooling block 50 and is tensioned by a tension spring 85, in particular by a self-contained ring spring, whereby this ring spring generates a radial tensile force. Fig. 32 shows another variant of the convection protection 25 from the detailed view III of Fig. 28. In addition to what has already been said about Fig. 29, the convection protection 25 has an extended end. This extended end includes, on the one hand, a stiffener 80 which is longer and curved than in Fig. 29 and, on the other hand, a shaft seal 81, shown here in the form of an axial sealing lip 84. The axial sealing lip 84 is in contact with the heat sink 50. Fig. 33 to 35 show various positions of the tiltable extrusion head 1 from Fig. 1. In a preferred embodiment, as shown in Fig. 33 to 35, as already described above, the extrusion head 1 can be attached to the support bracket 28 by means of the tilt shaft 38 in front of the rear panel 73, in other words within the mounting structure 66. The tilt actuator 29 can subsequently tilt the extrusion head 1 via the tilt shaft 38 which runs through the support bracket 28 and can preferably serve as a force transmission device. The plane in which the extrusion head 1 can be tilted can be the YZ plane, as shown in Fig. 33 to 35. In other words, the tilt shaft 38 thus represents a pivot shaft and/or a transmission shaft. Thanks to the tiltable extrusion head 1, the offset unit 6 with the condenser units 7 can be arranged in such a way that only one nozzle 77 of a condenser unit 7 can be used for the contact-free printing of the at least one extrusion material 3. Because the nozzle in use is arranged furthest down in the Z direction, there is no risk of the other nozzles of the condenser units 7 touching the product and/or the last printed layer when the extrusion head 1 located in the assembly structure 66 is moved. This applies in particular under the assumption that during contact-free printing a product is built up layer by layer in the Z direction and that the extrusion head 1 located in the assembly structure 66 is moved in the XY plane to build up each individual layer. In the vertical starting position, in which the extrusion head 1 is aligned with all of its condenser units 7 along the Z direction, as shown in Fig. 34, the extrusion head 1 can be tilted in two directions. The extrusion head 1 can be tilted in two directions, making it possible to move the extrusion head 1 into two tilt positions. This can be particularly advantageous when multiple condenser units 7 are used, with some of the existing condenser units 7 representing a first set 21 and the remaining part of the condenser units 7 representing a second set 22. The first set 21 of the condenser units 7 can print a first extrusion material 3 with different levels of accuracy due to condenser units 7 of the first set 21 having different nominal widths of the nozzle channels 23. In contrast, the second set 22 of the condenser units 7 can print a second extrusion material 3 with different accuracy due to condenser units 7 of the second set 22 with different nominal widths of the nozzle channels 23. It is therefore possible, in a first inclination position of the extrusion head 1, shown in Fig. 35, to use the first set 21 for structural construction of a product and to switch between different condenser units 7 of the first set 21 with different nozzle nominal widths in this first inclination position. When changing materials, the extrusion head can be moved from the first inclination position to the second inclination position, shown in Fig. 33, so that the second set 22 can be used for the structural construction of a support structure, wherein in this second inclination position it is possible to switch between different condenser units 7 of the second set 22 with different nozzle nominal widths. In order to prevent an undesired condenser unit 7 from being used in one of the possible inclination positions of the extrusion head 1, a stop 27 can be used to prevent the offset unit 6 from being over-rotated and/or a locking means 26 can be used to prevent it from becoming loose, whereby only a specific condenser unit 7 and/or a specific number of condenser units 7 and/or a specific set of condenser units 7 can be used. Fig. 36 shows a perspective view of the extrusion head 1 with the mounting structure 66 from Fig. 35, implemented in a travel system 71. When the mounting structure 66 is connected to the extrusion head 1, the mounting structure 66 together with the extrusion head 1 can be arranged within a travel system 71. With the aid of displacement devices 76 of the displacement system 71, the assembly structure 66 including the extrusion head 1 can be moved, wherein it is preferably provided that the assembly structure 66 including the extrusion head 1 can be moved in two, particularly preferably three directions. In a preferred embodiment, as shown in Fig. 36, a convection guard 25 can be provided between the mounting structure 66 and at least one travel device 76 of the travel system 71. The convection guard between the mounting structure 66 and at least one travel device 76 of the travel system 71 can consist of one or more parts, in particular one or more folding roof covers. What has been said so far about the convection guard 25 in Fig. 28 also applies to the convection guard 25 in Fig. 36. In Fig. 36, in addition to the convection guard described in Fig. 28, a convection guard is also provided, which is arranged between the travel system 71 and the mounting structure 66. Analogous to the shielding in Fig. 28, in the embodiment variant of Fig. 36, shielding is provided by this extended arrangement. The shield, which is also extended in this way, separates the operating space over the entire span of the travel system in the XY plane, analogously to that explained above for Fig. 28, into a drive space above the shield and a construction space below the shield. In this way, thermal shielding of the construction space from the drive space can be achieved. Fig. 37 shows an arrangement of the extrusion head 1 within the mounting structure 66 and a first platform 86. In this illustration, the extrusion head 1 is in an inclined position within the mounting structure 66 and is arranged in such a way that printing can be done on the platform 86 via one of the nozzles 77 or one of the condenser units 7. In a preferred embodiment, it can be provided that the extrusion head 1 together with the mounting structure 66 and/or the platform 86 are height-adjustable or adjustable. Fig. 38 shows an arrangement of the extrusion head 1 within the mounting structure 66 and a second platform 86. This embodiment differs from the embodiment from Figure 37 in that the platform 86 is designed as a rotary table. In a preferred embodiment, the platform 86 can be designed as a rotary table, the axis of rotation of which is preferably aligned in the Z direction, in order to provide an additional, for example fifth axis for 5-axis additive manufacturing in order to preferably produce complex geometries with undercuts layer by layer without the use of support structures, wherein the fourth axis can be realized by the tiltable extrusion head 1, more specifically by the tilt actuator 29. This can have the advantage that, by eliminating support structures, a different material with, for example, different material properties such as color and so on can be used. This results in time and cost savings. If the extruder is the fourth axis of the five-axis system, this can lead to lower energy requirements. Fig. 39 shows an exploded view of the support bracket 28, the tilt actuator 29, the tilt shaft 38 or swivel shaft 93 and the travel system 71. In this view in Fig. 39, the tilt shaft 38 is a swivel shaft 93. The swivel shaft 93 is located in a swivel shaft bearing seat 87 of the support bracket 28 when installed. The pivot shaft 93 is in contact with the support bracket 28 via a pivot shaft bearing 94 next to the pivot shaft collar 92. At least one bearing cover 90 can be provided to secure the pivot shaft bearing 94. The grooved nut 88 can serve to axially secure the material feed unit 2 to the pivot shaft 93. The grub screw 89 can serve to secure the grooved nut 88. The pivot shaft 93 can be connected to the material feed unit 2 on the one hand and to the motor shaft of the tilt actuator 29 on the other hand via the key connections 91. The extrusion head 1 can be axially secured as a whole unit, as can be seen in Fig. 3, due to the pivot shaft 93, preferably designed with key connections 91 and a grooved nut 88. For maintenance purposes and/or repairs, the extrusion head 1 can be removed from the support bracket 28, preferably from the pivot shaft 93, in a short time, with little effort and at low cost from the arrangement shown in Fig. 33 to 36 by loosening the groove nut 88. To completely remove the extrusion head 1 from the system, the convection protection 25 can be removed by loosening the convection protection connection device 39. The support bracket 28 has the mounting structure connection devices 95 for connection to the mounting structure 66, the carriage connection devices 103 for connection to the carriage 104 and the tilt actuator connection devices 99 for connection to the tilt actuator 29. In addition, the arrangement in Fig. 39 has the following components in and/or on the support bracket 28: a wedge lock washer 96, an adjusting screw 97, a lock nut 98, the Setting screw 97 can serve as an adjustable stop for the pivot shaft 93, in particular for the pivot shaft collar 92, a threaded spindle 100, a spindle nut 101, whereby the spindle nut 101 can be a component of the support bracket 28, and a lubrication point 102. The support bracket 28 can, as already mentioned, be connected to the carriage 104 via the carriage connection devices 103. The carriage 104 is part of the travel system 71, which additionally has the profile rail guide 105 along which the carriage 104 can be moved.

List of reference symbols: 1 Extrusion head 2 Material feed unit 3 Extrusion material 4 Separating device 5 Blade element 6 Offset unit 7 Condenser unit 8 Blade connection device 9 Cutting surface underside 10 Cutting surface upper side 11 Cutting edge 12 First cutting surface section 13 Second cutting surface section 14 Introductory line 15 Blade element hollow volume 16 First conveyor device 17 Continuation line 18 Holding device 19 Cooling device 20 Cooling rotary feedthrough 21 First set of condenser units 22 Second set of condenser units 23 Nozzle channels 24 Cable feedthrough 25 Convection protection 26 Locking means 27 Stop 28 Support bracket 29 Tilt actuator Offset actuator First extrusion actuator Second extrusion actuator First material receiving port Second material receiving port Extrusion block Offset unit receiving block Shroud Inclination shaft Anti-convection connector Second conveyor Feed wheel Inclined side wall Rear wall Piping First material feed hose Second material feed hose Drive wheel Material feed unit heat sink Bearing Offset unit cooling block Stop recess Nozzle tube Washer Lock recess Blade element bottom Blade element top Projection Guide recess Nozzle tip shield Coolant interface Heater block Centering means Transmission gear Receiving element Distributor Assembly structure Longitudinal direction Measuring device Rotation axis Stop guide Travel system Locking means Rear cover Side cover Front cover Travel device Nozzle Nozzle tip Nozzle groove Reinforcement Shaft seal Labyrinth seal Radial sealing lip Axial sealing lip Tension spring Platform Pivot shaft position seat Groove nut Grub screw Bearing cover Key connection Pivot shaft collar Pivot shaft Pivot shaft bearing Assembly structure connection device Wedge lock washer Adjusting screw Lock nut Tilt actuator connection device Threaded spindle Spindle nut Lubrication point Carriage connection device Carriage Profile rail guide

Claims

Patent claims 1. Extrusion head (1) for additive manufacturing, preferably based on the fused filament fabrication method, of a product comprising ^ at least one material feed unit (2) for feeding at least one extrusion material (3), preferably in filament form, ^ a separating device (4) for the at least one extrusion material (3), ^ at least one offset unit (6) with at least two liquefier units (7), wherein the at least one extrusion material (3) can be introduced into a first liquefier unit and the upper end of the extrusion material (3) severed by the separating device (4) can be introduced into a second liquefier unit, characterized in that the at least one offset unit (6) is rotatable, in particular rotatable as a turret head, and/or the extrusion head (1) is inclinable or inclined, preferably in relation to the longitudinal axis of the extrusion head (1). 2. Extrusion head (1) according to claim 1, characterized in that the at least one offset unit (6) is rotatable in two directions in one plane and/or the extrusion head (1) is inclinable in at least two directions starting from a vertical starting position. 3. Extrusion head (1) according to one of claims 1 or 2, characterized in that the extrusion head (1) is arranged at least in one plane, in particular in relation to the longitudinal axis of the Extrusion head (1) can be tilted to two sides within one plane. 4. Extrusion head (1) according to one of claims 1 to 3, characterized in that the offset unit (6) has at least two, preferably six, liquefier units (7), wherein a first extrusion material can be extruded by a first set (21) of the existing liquefier units (7) and a second extrusion material can be extruded by a second set (22) of the existing liquefier units (7). 5. Extrusion head (1) according to one of claims 1 to 4, characterized in that the at least two condenser units (7) have nozzle channels (23), wherein the at least two condenser units (7) or the nozzle channels (23) are arranged inclined to one another and/or to a rotation axis (69) of the offset unit (6). 6. Extrusion head (1) according to one of claims 1 to 5, characterized in that at least one locking means (26) is provided, wherein at least one position of the offset unit (6) relative to the material feed unit (2) can be determined by the at least one locking means (26). 7. Extrusion head (1) according to one of claims 1 to 6, characterized in that at least one stop (27) is provided, wherein the rotatability of the offset unit (6) in at least one direction, preferably in two directions, is limited by the at least one stop (27), preferably in combination with at least one stop guide (70). 8. Extrusion head (1) according to one of claims 1 to 7, characterized in that the material feed unit (2) and/or the offset unit (6) has a cable feedthrough (24), in particular an electrical rotary feedthrough and/or a cable screw connection. 9. Extrusion head (1) according to one of claims 1 to 8, characterized in that a platform (86), preferably designed as a turntable, is provided, wherein the product can be manufactured on the platform (86) by means of additive manufacturing. 10. Method and/or use for producing a product with an extrusion head (1) according to one of claims 1 to 9. 11. Method according to claim 10, characterized in that by tilting the extrusion head (1) the nozzle (77) of one of the existing condenser units (7) is moved into a position below the remaining nozzles (77) of the existing condenser units (7). 12. Method according to one of claims 10 or 11, characterized in that by rotating the offset unit (6) in the inclined state of the extrusion head (1), the nozzle (77) of one of the existing condenser units (7) is moved into a position below the remaining nozzles (77) of the existing condenser units (7). 13. Method according to one of claims 10 to 12, characterized in that the offset unit (6) has at least one set (21, 22) of at least two condenser units (7), wherein the at least two condenser units (7) of the set (21, 22) have two different nominal widths of the nozzles (77), and by rotating the Offset unit (6), preferably in the inclined state of the extrusion head (1), with different accuracy based on the nominal widths of the nozzles (77) of the at least two liquefaction units (7) a product is produced. 14. Method according to one of claims 10 to 13, characterized in that by tilting the extrusion head (1) starting from a vertical starting position in at least two directions, a material change between at least two different extrusion materials (3) takes place. 15. Method according to one of claims 10 to 14, characterized in that undercuts are taken into account in a product to be manufactured and the product is built up layer by layer with at least one extrusion material (3) by tilting the extrusion head (1) and/or by rotating the offset unit (6), wherein during the layer-by-layer construction by tilting the extrusion head (1) and/or by rotating the offset unit (6) a support structure for supporting the undercuts of the product is additionally built up with at least one other extrusion material (3).