Patent Publication Number: US-2020282594-A1

Title: Print head coater module for a 3D printer, use of the print head coater module and 3D printer including the print head coater module

Description:
The present invention relates to a print head coater module for a 3D printer, the use of the print head coater module and a 3D printer including the print head coater module. 
     Various generative manufacturing processes (and consequently various types of 3D printers, i.e. machines/constructions for building up a component in layers) are known. 
     Some generative manufacturing processes have the following steps in common:
         (1) First, particulate material (and particulate construction material, respectively) is applied over the entire surface of/continuously on a construction field, so as to form a layer of unsolidified particulate material.   (2) The applied layer of unsolidified particulate material is selectively solidified in a predetermined partial area (in accordance with the component part to be manufactured), for example by selectively printing a treatment agent, for example a binder (alternatively, for example, by laser sintering).   (3) Steps (1) and (2) are repeated to manufacture a desired component. For this purpose, a construction platform on which the component is built up in layers may, for example, be lowered by respectively one layer thickness before a new layer is applied (alternatively, the coater and the printing device may, for example, be raised by respectively one layer thickness).   (4) Finally, the manufactured component which is formed by the solidified partial areas and is supported and surrounded by loose, unsolidified particulate material may be unpacked.       

     The construction space in which the component or the components is/are manufactured may, for example, be defined or formed by a so-called construction box (also referred to as “job box”). A construction box of this type may have a circumferential wall structure which is open in an upward direction and extends in a vertical direction (for example formed by four vertical side walls), which may, for example, be formed to be rectangular when viewed from above. A height-adjustable construction platform may be received in the construction box. In this respect, the space above the construction platform and between the vertical circumferential wall structure may for example at least contribute to forming the construction space. An example of such a construction box is, for example, described in DE 10 2009 056 696 A1. However, the construction space may, for example, also be free at the side (at least in part), i.e. unlimited at the circumference (at least in part). An upper area of the construction space may, for example, be referred to as a construction field. 
     A coater (also referred to as a “recoater”) is normally used in the above step (1). Various coaters are known for use in 3D printers, by means of which a particulate construction material may be applied to the construction field (also referred to as construction surface or construction area) in the form of a uniform layer over the entire surface/a continuous layer. 
     One type of coater uses a roller (short: “roller coater”) in front of which first an amount of particulate construction material is put down before coating and which is then horizontally moved across the construction field to apply the particulate construction material in the form of a uniform layer onto the construction field. In this respect, the roller may be rotated opposite to the moving direction. 
     Another kind of coater (a so-called “container coater”, for example a “slot coater”) uses a container which defines an inner cavity for receiving particulate material, and has an output region (for example an elongated output region), for example comprising an (for example elongate) output slot, for outputting the particulate construction material. The container coater may, for example, be displaceable across a construction field or a construction space (for example horizontally, for example transverse to its longitudinal direction), wherein the particulate material can be output onto the construction field through the (elongate) output region to thereby apply a uniform/continuous construction material layer over the entire surface of the construction field. The coater may be elongate, for example to span or to cover the length or width of a (rectangular) construction field or construction space. The coater may, for example, be provided with a stroking/sweeping member by which construction material applied to the construction field may be stroked, to compress and/or level the construction material. 
     In the above step (2), a printing device having a print head may for example be used, which applies a treatment agent in a controlled way onto a partial area of the construction material layer applied before. The treatment agent contributes to a (direct and/or later) solidification of the particulate material layer in the partial area. For example, the treatment agent may be/contain a binder, for example a binder component of a multicomponent binder. 
     Alternatively, a laser may, for example, be used in the above step (2) to solidify a partial area of the construction material layer applied previously, in particular by sintering or melting the construction material in the partial area. 
     There are various approaches to increase the throughput of 3D printed components or 3D printers. DE 10 2014 112 447 A1 proposes a 3D printer including two construction spaces, each of which has respectively one coater assigned to it and is operated by a common/shared print head. Alternatively, the desired components could be printed simultaneously/in parallel in two separate 3D printers with one construction space each, to which a coater and a print head is assigned. 
     It may be considered as being an object of the invention to provide a 3D printer and/or a device for the same, by means of which high-quality components can be produced effectively. 
     For this purpose, the present invention provides a print head coater module for a 3D printer according to claim  1 , the use of a print head coater module according to claim  9  and a 3D printer according to claim  10 . Further configurations of the print head coater module are described in dependent claims  2 - 8 . Further configurations of the 3D printer are described in dependent claims  11 - 13 . 
     According to various aspects of the invention, a print head coater module for a 3D printer has a print head, a coater including a container defining an inner cavity for receiving particulate material (for example, sand particles, for example, metal particles, for example, plastic particles) and opening into an output opening from which the particulate material can be discharged (for example, to a/the construction field of the 3D printer, for example, in the direction of a/the construction space of the 3D printer, for example continuously during a journey over a/the construction space of the 3D printer) (for example by means of a dosing mechanism, for example comprising a dosing roller and/or an ultrasonic device and/or a shaker device), and a roller assembly arranged between the container and the print head, and a common (for example frame-shaped) support structure to which the print head, the container and the roller assembly are attached, so that the print head, the container and the roller assembly can be moved over a construction space of the 3D printer together. 
     The arrangement of print head and coater in one module makes it possible that several construction spaces arranged one after the other are served by both the same print head and the same coater in succession. Since each construction space is served by the same coater and the same print head, a uniform quality of the 3D printed components can be achieved in the different construction spaces, so that eventually high-quality components can be manufactured or deficient products or complex adjustment work can be reduced or eliminated. Compared to the initially described approaches to increase the throughput of 3D printed components or 3D printers, one or more coaters can be saved in addition, which are otherwise/to date assigned to a particular construction space. Finally, by using such a coater in the module, comprising a container and a roller assembly (instead of, for example, a coater including a container and a stroking/sweeping blade), the coating speed can be increased, which otherwise would be a limiting factor for the speed of the print head coater module. The roller assembly is thus able to compensate, at least to some extent, for any loss of printing speed that would otherwise be associated with combining into a module. In this respect, the container may primarily assume the function of outputting a controlled quantity, the roller assembly being able to assume the function of (fine) distribution and compression, i.e. said functions may be separated from each other. 
     For example, the print head, the container, the output opening and/or the roller assembly may be elongated. The output opening may, for example, be located on a side of the coater facing the construction space. The container may, for example, comprise a closing device, for example to close the output opening (tightly and/or completely), for example such that no particulate material is output from the output opening. 
     The roller assembly may, for example, comprise a first roller and a second roller. The first roller may, for example, be arranged between the container and the second roller. For example, the second roller may be arranged between the first roller and the print head. For example, the first roller and/or the second roller may be elongated. For example, the first roller may be a distribution roller. For example, the first roller may be configured to distribute particulate material output from the container, for example (evenly) over the construction field (i.e., over a/the upper region of the construction space). The second roller may, for example, be a compression roller. The second roller may, for example, be configured to compress particulate material output from the container (and distributed by the first roller), for example evenly, for example to a predetermined degree of compression. 
     By using a first roller and a second roller in the roller assembly, the coating speed may be (further) increased. The first roller may (evenly) distribute particulate material output from the container over the construction field (i.e. the upper region of the construction space) and the second roller may compress the particulate material distributed by the first roller (to a desired degree of compression). This means that the first roller may assume the function of distributing the particulate material and the second roller may assume the function of compressing the particulate material. These functions may thus be separated from each other, which allows the coating speed to be increased. 
     The first roller may, for example, comprise a structured surface. The structured surface of the first roller may, for example, comprise one or more recesses. For example, the structured surface of the first roller may comprise one or more protrusions. The recesses and/or protrusions may, for example, be formed by removing material from a part of a/the surface of a/the roller and/or by applying material to a part of a/the surface of a roller. 
     By structuring the surface of the first roller, the particulate material output from the container can be particularly well distributed. By structuring the surface of the first roller, a particularly even distribution of the particulate material over the construction field can be achieved. 
     The structure of the surface of the first roller may, for example, comprise at least one groove (for example elongated, for example formed by recesses and/or protrusions), for example a plurality of grooves, for example 2-40 grooves, for example 2-30 grooves, for example 2-20 grooves, for example 2-10 grooves. The at least one groove may, for example, be inclined relative to the roller longitudinal axis, for example in the form of a helix winding around a/the roller longitudinal axis. The at least one groove may, for example, form the above-mentioned recess(es). 
     The structure of the surface of the first roller may, for example, comprise a honeycomb structure (formed by recesses and/or protrusions, for example), for example a diamond-shaped honeycomb structure. 
     The second roller may comprise a smooth surface, for example. For example, the surface of the second roller may have a roughness Rz (average surface roughness) of less than/equal to 250 μm, for example less than/equal to 200 μm, for example less than/equal to 150 μm, for example less than/equal to 100 μm, for example less than/equal to 75 μm, for example less than/equal to 50 μm, for example less than/equal to 25 μm, for example less than/equal to 10 μm, for example less than/equal to 5 μm, for example less than/equal to 1 μm, for example less than/equal to 0.5 μm, for example less than/equal to 0.1 μm, for example less than/equal to 0.01 μm. The surface of the second roller may, for example, be coated. The coating may, for example, be made of Teflon, hard metal, ceramic and/or combinations thereof. The surface of the second roller may, for example, be ground, polished, smoothed and/or lapped. 
     The smooth surface of the second roller allows the particulate material to be compressed particularly well. Due to the smooth surface of the second roller, the particulate material can be compressed in a particularly even way. 
     The first roller and/or the second roller may, for example, be a hollow roller. The first roller and/or the second roller may for example be made of metal, plastic, steel, stainless steel, aluminum, titanium, glass fiber reinforced plastic (GRP), carbon fiber reinforced plastic (CFRP) and/or combinations thereof. The first roller and/or the second roller may, for example, have a diameter in the range of 5-500 mm, for example in the range of 10-400 mm, for example in the range of 20-300 mm, for example in the range of 30-200 mm. 
     The second roller may, for example, be height-adjustable in relation to the support structure (for example, adjustable in a z-direction, for example, adjustable in a vertical direction). The height adjustment may be done manually, for example, or by means of a lift drive integrated in the print head coater module. The print head coater module may, for example, have a control device that is configured to control the lift drive, for example so that the second roller is adjustable in a height direction (for example in a z-direction, for example in a vertical direction) relative to the support structure. 
     The roller longitudinal axis of the first roller and the roller longitudinal axis of the second roller may, for example, be (substantially) parallel to each other. 
     For example, the print head coater module may have its own support structure drive integrated into the print head coater module for moving the support structure along a rail system. The support structure drive may, for example, be an electric motor that drives wheels or other output means arranged on the support structure. For example, the print head coater module may have a/the control device configured to control the carrier structure drive, for example so that the carrier structure or print head coater module is movable along a/the rail system. 
     For example, the print head coater module may comprise an integrated first roller rotary drive for rotational movement of the first roller. For example, the first roller rotary drive may rotationally move the first roller in a direction of rotation opposite to the direction of movement of the support structure and/or the print head coater module. The first roller rotary drive may rotationally move the first roller, for example in a counter direction. For example, the print head coater module may comprise a/the control device that is configured to control the first roller rotation drive, for example in a way that the first roller can be rotationally moved in a direction of rotation opposite to the direction of movement of the support structure and/or the print head coater module, for example in a way that the first roller can be rotationally moved in a counter direction. 
     A rotational movement in a direction of rotation opposite to the direction of movement of the support structure and/or a rotational movement in a counter direction is understood as being a rotational movement which is opposite to a direction of rotation in which a freely rotating roller would rotate if the print head coater module was/is moved over a surface. 
     For example, the print head coater module may have an integrated second roller rotary drive for rotational movement of the second roller. For example, the second roller rotary drive may rotationally move the second roller in a direction of rotation opposite to and/or in the direction of the direction of movement of the support structure and/or the print head coater module. The second roller rotary drive may, for example, rotationally move the second roller in the counter direction and/or in the running direction. The print head coater module may, for example, have a/the control device configured to control the second roller rotary drive, for example in a way that the second roller can be moved rotationally in a direction of rotation opposite to and/or in the direction of the direction of movement of the support structure and/or the print head coater module, for example in a way that the second roller can be moved rotationally in the counter direction and/or in the running direction. 
     A rotational movement in a direction of rotation in the direction of the direction of movement of the support structure and/or a rotational movement in the running direction is understood as being a rotational movement corresponding to a direction of rotation in which a freely rotating roller would rotate if the print head coater module was/is moved over a surface. 
     If the second roller is rotationally moved in a direction of rotation in the direction of the direction of movement of the support structure and/or in the running direction, the particulate material can be compressed particularly well. 
     The print head coater module may, for example, comprise an integrated second roller lift drive for height-adjusting (for example, in the z direction, for example, adjusting in the vertical direction) of the second roller (relative to the support structure). The print head coater module may for example have a/the control device adapted to control the lift drive, for example so that the second roller is adjustable in a height direction (for example in the z direction, for example in the vertical direction) (relative to the support structure). 
     The print head and/or the container and/or the roller assembly may, for example, each be attached immovably (for example rigidly) to the support structure in a horizontal plane (for example in an x direction and a y direction, for example in an x/y plane). This means that the print head and/or the container and/or the roller assembly may, for example, be arranged on the support structure so that they are not movable (for example, not displaceable) in a horizontal direction. 
     For example, the print head may be configured to apply a treatment agent (for example a binder, for example a binder agent) in a controlled way to a partial region of a layer of particulate material previously applied by the coater. The treatment agent may, for example, contribute to an (immediate and/or subsequent) solidification of the particulate material layer in the partial region. For example, the treatment agent may be/contain a binder agent, for example a binder component of a multicomponent binder. For example, the print head may be a binder jetting print head. 
     For example, the print head and/or the container may be segmentable (in a longitudinal direction). This means that the print head and/or the container may, for example, consist of several segments which are arranged one after the other, for example in the longitudinal direction. The container may, for example, comprise a/the closing device. For example, the closing device may be segmentable (in a longitudinal direction). This means that the closing device may, for example, consist of several (closing) segments, which are, for example, configured to (tightly) close a partial region of the output opening. 
     The print head coater module may, for example, be a bidirectionally configured print head coater module that is configured to coat and/or print in two directions of travel. The bidirectionally configured print head coater module may, for example, comprise a print head and two coaters, each with one container and one roller assembly, wherein, for example, the print head may be located between the two roller assemblies, and the print head and the two roller assemblies may be located between the two containers, wherein, for example, each roller assembly may comprise a first roller and a second roller, wherein, for example, the print head may be located between the two second rollers, the print head and the two second rollers may be located between the two first rollers, and the print head, the two first rollers and the two second rollers may be located between the two containers. The bidirectionally configured print head coater module may, for example, be configured with two print heads, a container and two roller assemblies, wherein, for example, the container may be located between the two roller assemblies, and the container and the two roller assemblies may be located between the two print heads, wherein, for example, each roller assembly may comprise a first roller and a second roller, wherein, for example, the container may be located between the two first rollers, the container and the two first rollers may be located between the two second rollers, and the container, the two first rollers and the two second rollers may be located between the two print heads. The elements/components (for example, print head and/or coater and/or container and/or roller assembly and/or support structure and/or first roller(s) and/or second roller(s)) of the bidirectionally configured print head coater module may, for example, be configured as described above. 
     The print head coater module may, for example, be used for applying in layers and selectively printing layers of sand, such as foundry sand. The print head coater module may, for example, be used for 3D printing of casting molds and/or foundry cores. The print head coater module may, for example, be used for collective applying in layers and selectively printing particulate material in several construction fields arranged in series, for example formed by a respective construction platform, which is, for example, received in a respective construction box. 
     According to various aspects of the invention, a 3D printer has a print head coater module according to any one of the aspects described above, a plurality of construction spaces arranged one after the other in series, and a rail system along which the print head coater module can be moved across the plurality of construction spaces. 
     The construction spaces may, for example, each define an elongate construction field (for example, a rectangular construction field) and may be arranged one after the other in series in such a way that the construction fields are aligned with their longitudinal axes one after the other and/or in extension of each other, for example without spacing, for example, directly one after the other. The longitudinal axes of the construction fields may, for example, be congruent. The rail system may, for example, comprise one or more rails (for example two rails) whose longitudinal axes extend (essentially) parallel to the longitudinal axes of the construction fields. The print head coater module may, for example, be displaceable (for example along the one or more rails) in a direction that is (essentially) parallel to the longitudinal axes of the construction fields. 
     For example, in a top view, the construction spaces may have two long sides and two short sides and may, for example, be arranged adjacent to each other along a (respectively) short side, for example without any spacing, for example directly next to each other. The rail system may, for example, have one or more rails (for example two rails) whose longitudinal axes extend, for example, (essentially) parallel to the long sides of the construction spaces. The print head coater module may, for example, be displaceable (for example along the one or more rails) in a direction that is (essentially) parallel to the long sides of the construction spaces. 
     The arrangement of the construction spaces allows the lengths of the components (such as the print head and/or roller assembly) of the print head coater module to be reduced. This means that, for example, shorter roller(s) (assemblies) and/or shorter print heads can be used. This makes it possible to reduce deflection of the roller(s) (assembly), which improves the quality of the 3D printed components. In addition, a shorter print head can be used, which is less expensive. 
     A construction space may, for example, be formed by a construction box. For example, a construction box may have a height-adjustable construction platform. A construction box may, for example, have side walls. The construction spaces may, for example, be arranged adjacent to each other in such a way that two adjacent construction boxes have a common side wall. The common side wall may, for example, be removable, so that two adjacent construction spaces are connectable to form a larger construction space. The common side wall may, for example, form a partition between two (adjacent) construction spaces. The construction platforms of the respective construction spaces may, for example, be independently height-adjustable. 
     For example, the 3D printer may have a channel structure (for example in the form of a gutter) that extends underneath the plurality of construction boxes. The construction boxes may, for example, be configured to discharge loose particulate material downwards into the channel structure. The channel structure may, for example, be inclined and/or may comprise a particulate material conveyor device (for example a conveyor belt). 
     For example, the 3D printer may comprise a first and a second turning device located at a/the first and a/the second longitudinal end of the series of construction spaces (or construction boxes), respectively, and configured to turn the print head coater module so that after a first journey over the construction spaces (and/or construction boxes), the print head coater module is ready for a second journey over the construction spaces (and/or construction boxes) in the reverse direction. The turning device may, for example, be a turn table or a turning platform. 
     The 3D printer and/or the print head coater module may, for example, comprise a control device that controls the print head coater module so that it coats and prints during a first journey over the construction spaces (and/or construction boxes) and performs an idle run during a second journey over the construction spaces (and/or construction boxes) which takes place in the opposite direction to the direction of the first journey. 
     The 3D printer and/or the print head coater module may, for example, comprise a/the control device that controls the print head coater module in a way to coat during a first journey over the construction spaces (and/or construction boxes) and to print during a second journey over the construction spaces (and/or construction boxes) which takes place in the opposite direction to the direction of the first journey. 
     For example, the 3D printer and/or the print head coater module may have a control device (for example, a common control device) that is configured to perform the above-mentioned control functions. 
     For example, the 3D printer may comprise a return path connecting the first longitudinal end of the series of construction spaces (and/or construction boxes) to the second longitudinal end of the series of construction spaces (and/or construction boxes) to return the print head coater module to the first longitudinal end after a first journey over the construction spaces (and/or construction boxes) starting from the first longitudinal end towards the second longitudinal end during which the print head coater module coats and prints. 
     For example, the print head coater module may be configured bidirectionally to coat and print during both a first journey and a second journey over the construction spaces (and/or construction boxes). The bidirectionally configured print head coater module may, for example, comprise one print head and two coaters, each formed by a container and a roller assembly. The bidirectionally configured print head coater module may, for example, comprise two print heads, a container and two roller assemblies. 
    
    
     
       Exemplary but non-limiting embodiments of the present invention are shown in the Figures and are hereinafter described in detail. 
         FIG. 1  shows a perspective view of a print head coater module for a 3D printer according to a first embodiment. 
         FIG. 2  shows a perspective view of a print head coater module for a 3D printer according to a second embodiment. 
         FIG. 3  shows a perspective view of a coater that can be used in the print head coater module according to the first and/or second embodiment. 
         FIG. 4  shows a perspective view of a first roller that can be used in the print head coater module of the first and/or second embodiment and/or in the coater shown in 
         FIG. 3 . 
         FIG. 5  shows a front view of another first roller that can be used in the print head coater module according to the first and/or second embodiment and/or in the coater shown in  FIG. 3 . 
         FIG. 6  shows a perspective view of a 3D printer according to a third embodiment in which the print head coater module according to the first embodiment is used. 
         FIG. 7  shows a perspective view of a 3D printer according to a fourth embodiment in which the print head coater module according to the second embodiment is used. 
     
    
    
     In the following detailed description, reference is made to the enclosed Figures which are incorporated therein and in which specific embodiments are shown by way of illustration, according to which the invention can be performed. In this respect, the terms indicating a direction, such as “up”, “down”, “front”, “rear”, etc. are used with reference to the orientation in the described Figure(s). As components of embodiments may be positioned in a number of different orientations, the terminology indicating the different directions serves for illustration and shall not be restrictive in any way. 
     It shall be understood that other embodiments may be used and structural or logical changes may be made without deviating from the scope of protection of this invention. It goes without saying that the features of the various exemplary embodiments described herein may be combined unless specified otherwise. Thus, the following detailed description should not be understood in a restrictive sense and the scope of protection of this invention shall be defined by the attached claims. 
     In this description, terms such as “connected”, “attached” and “coupled” may be used to describe both a direct and indirect connection, a direct or indirect attachment and a direct or indirect coupling. 
     In the Figures, identical or similar elements are provided with identical reference numbers where appropriate. 
       FIG. 1  shows a perspective view of a print head coater module  10  for a 3D printer  42  according to a first embodiment.  FIG. 2  shows a perspective view of a print head coater module  10  for a 3D printer  42  according to a second embodiment.  FIG. 3  shows a perspective view of a coater  14  that can be used in the print head coater module  10  according to the first and/or second embodiment.  FIG. 4  shows a perspective view of a first roller  24  that can be used in the print head coater module  10  according to the first and/or second embodiment and/or in the coater  14  shown in  FIG. 3 .  FIG. 5  shows a front view of another first roller  24  that can be used in the print head coater module  10  according to the first and/or second embodiment and/or in the coater  14  shown in  FIG. 3 . 
     As shown in  FIGS. 1 and 2 , the print head coater module  10  for a 3D printer  42  according to the first and/or second embodiment has a print head  12 , a coater  14  with a container  16  defining an internal cavity  18  for receiving particulate material (for example sand particles, for example metal particles, for example plastic particles) and opening into an output opening, from which the particulate material can be output, and a roller assembly  20 , which is arranged between the container  16  and the print head  12 , and a common support structure  22 , to which the print head  12 , the container  16  and the roller assembly  20  are attached, so that the print head  12 , the container  16  and the roller assembly  20  are displaceable together over a construction space of the 3D printer  42 . 
     For example, the output opening may be located on the lower side of container  16 . This means that, in  FIGS. 1-3 , for example, the output opening may be located along the z direction below the inner cavity  18 , at a lower end of container  16 . 
     As shown in  FIGS. 1-3 , the roller assembly  20  may, for example, comprise a first roller  24  and a second roller  26 , the first roller  24  being located between the container  16  and the second roller  26 . 
     For example, the first roller  24  may have a structure surface  28  (not shown in  FIG. 1 ; shown in  FIGS. 2-5 ). The second roller  26  may, for example, have a smooth surface  56  (shown in  FIGS. 1-3 ). 
     For example, the structure of the surface of the first roller  24  may comprise at least one groove  30 , for example a plurality of grooves  30 , wherein the at least one groove  30  may optionally be inclined with respect to the roller longitudinal axis  32 , for example in the form of a helix winding around the roller longitudinal axis  32 . A first roller  24  with a groove  30  in the form of a helix is, for example, shown in  FIG. 2 , and a first roller  24  with a plurality of grooves  30  in the form of a helix is, for example, shown in  FIGS. 3 and 4 . Such first rollers  24  may, for example, be used in the first and/or second embodiment of the print head coater module  10  shown in  FIGS. 1 and 2 . 
     For example, the structure of the surface of the first roller  24  may comprise a honeycomb structure  34 , for example a rhombus/diamond-shaped honeycomb structure  34 . A first roller  24  with a honeycomb structure is shown in  FIG. 5 , for example. Such a first roller  24  may be used, for example, in the first and/or second embodiment of the print head coater module  10  shown in  FIGS. 1 and 2 . 
     The surface of the first roller  24  may, for example, be structured by removing material from the surface of a roller blank and/or by applying material to the surface of a roller blank. 
     The surface of the second roller  26  may, for example, be ground, polished, smoothed and/or lapped, for example to smooth the surface, for example to obtain a desired roughness Rz (average surface roughness) of the surface. 
     The second roller  26  may, for example, be height-adjustable in relation to the support structure  22 . This means that the second roller  26  may, for example, be adjustable in the z direction (see  FIGS. 1-3 ). 
     The print head coater module  10  according to the first and/or second embodiment may, for example, comprise its own support structure drive (not shown in the Figures) integrated into the print head coater module  10  for moving the support structure  22  or the print head coater module  10  along a rail system  36 . For example, the support structure drive may drive wheels  58  arranged on the support structure  22 . As an alternative or in addition to the wheels  58 , other suitable output means may also be used. For example, the wheels  58  may be placed onto the rail system  36 , for example so that the support structure  22  or the print head coater module  10  can be moved along the rail system  36 . 
     The print head coater module  10  according to the first and/or second embodiment may, for example, comprise an integrated first roller rotary drive  38  for rotationally moving the first roller  24 , for example in a direction of rotation opposite to the direction of movement of the support structure  22  and/or in the counter direction. 
     As illustrated in  FIG. 1 , a rotational movement of the first roller  24  in a direction of rotation opposite to the direction of movement of the support structure  22  and/or a rotational movement of the first roller  24  in a counter direction is understood as being a rotational movement in the direction of arrow  82 , when the print head coater module  10  is displaced/moved in the direction of arrow  80 . 
     The print head coater module  10  according to the first and/or second embodiment may, for example, comprise an integrated second roller rotary drive  40  for rotationally moving the second roller  26 , for example in a direction of rotation in the direction of the direction of movement of the support structure  22  and/or in the direction of travel. 
     As illustrated in  FIG. 1 , a rotational movement of the second roller  26  in a direction of rotation in the direction of the direction of movement of the support structure  22  and/or a rotational movement of the second roller  26  in the direction of travel is understood as being a rotational movement in the direction of arrow  84 , when the print head coater module  10  is displaced/moved in the direction of arrow  80 . 
     For example, the print head coater module  10  according to the first and/or second embodiment may comprise an integrated second roller lift drive for height-adjusting the second roller  26  (not shown in the Figures). 
     For example, the print head  12  and/or the container  16  and/or the roller assembly  20  may each be attached immovably/rigidly to the support structure  22  in a horizontal plane (i.e., in a/the x/y plane in  FIGS. 1 and 2 ). However, the print head  12  and/or the container  16  and/or the roller assembly  20  may, for example, be attached to the support structure  22  to be displaceable/movable in the z direction and/or tiltable along a respective longitudinal axis (axes) and/or turnable and/or rotatable. 
     As shown in  FIG. 3 , the coater  16  may for example comprise a coater support structure  60  to which the container  16 , the roller assembly  20  (and/or the first roller  24  and/or the second roller  26 ), the first roller rotary drive  38  and/or the second roller rotary drive  40  may be attached. Also, the second roller lift drive may be attached to the coater support structure  60 , for example (not shown in  FIG. 3 ). For example, the coater support structure  60  may be attached to the support structure  22 , for example so that the container  16 , the roller assembly  20  (and/or the first roller  24  and/or the second roller  26 ), the first roller rotary drive  38 , the second roller rotary drive  40  and/or the second roller lift drive can be attached to the support structure  22  by means of the coater support structure  60  (for example indirectly via the coater support structure  60 ). 
     The print head coater module  10  according to the first and/or second embodiment may, for example, comprise a control unit (not shown in the Figures) which is configured to control the first roller rotary drive  38 , the second roller rotary drive  40  and/or the second roller lift drive, for example to control the above-described functions (for example turning/rotating and/or height-adjusting). 
     As shown in  FIG. 2 , the print head coater module  10 , according to the second embodiment, may, for example, be configured to be bidirectional (to coat and/or print in both directions of travel) and may comprise a/one print head  12  and two coaters  14 , each with a container  16  and a roller assembly  20 , wherein, for example, the print head  12  may be located between the two roller assemblies  20  and the print head  12  and the two roller assemblies  20  may be located between the two containers  16 , wherein, for example, the roller assembly  20  may comprise a first roller  24  and a second roller  26 , and wherein, for example, the print head  12  may be located between the two second rollers  26 , the print head  12  and the two second rollers  26  may be located between the two first rollers  24 , and the print head  12 , the two second rollers  26  and the two first rollers  24  may be located between the two containers  16 . All elements/components (such as print head  12 , coater  14 , container  16 , roller assembly  20 , first rollers  24  and/or second rollers  26 ) of the bidirectionally configured print head coater module  10  according to the second embodiment may be configured as described above, for example. 
     An alternative embodiment (not shown in the Figures) of the print head coater module  10 , which may be configured to be bidirectional, may for example comprise two print heads  12 , two roller assemblies  20  and a/one container  16 , wherein, for example, the container  16  may be located between the two roller assemblies  20  and the container  16  and the two roller assemblies  20  may be located between the two print heads  12 , and wherein, for example, the print head  12 , the container  16  and/or the roller assembly  20  may be configured as described above. Such an arrangement could be obtained, for example, by mirroring the arrangement of print head  12 , roller assembly  20  and container  16  shown in  FIG. 1  on a/the longitudinal axis of container  16 . 
     The elements/components described above may be used for all embodiments of the print head coater module  10 . 
     The print head coater module  10  may, for example, be used (a) for applying in layers and selectively printing of layers of sand, for example foundry sand, and/or (b) for 3D printing of casting molds and/or foundry cores, and/or (c) for collectively applying in layers and selectively printing particulate material in several construction fields  46  arranged in series, for example formed by a respective construction platform which is received, for example, in a respective construction box  48 . 
       FIG. 6  shows a perspective view of a 3D printer  42  according to a third embodiment in which the print head coater module  10  according to the first embodiment is used.  FIG. 7  shows a perspective view of a 3D printer  42  according to a fourth embodiment in which the print head coater module  10  according to the second embodiment is used. 
     As shown in  FIGS. 6 and 7 , a 3D printer  42  according to the third and/or fourth embodiment has a print head coater module  10  for a 3D printer, a plurality of construction spaces  44  arranged in series one after the other, and a rail system  36  along which the print head coater module  10  is displaceable across the plurality of construction spaces  44 . The print head coater module  10  may, for example, be any one of the print head coater modules  10  described above, for example a print head coater module  10  according to the first embodiment (as shown in  FIG. 6 ), for example a print head coater module  10  according to the second embodiment (as shown in  FIG. 7 ). 
     A (respective) construction space  44  may, for example, be formed by a construction box  48 . A (respective) construction box  48  may, for example, have a height-adjustable construction platform (not shown in the Figures) and side walls. The (respective) construction platforms of the (respective) (for example adjacent) construction boxes  48  may, for example, be independently controllable (for example height-adjustable), for example by means of a/the control device. The construction spaces  44  or the construction boxes  48  may, for example, be arranged adjacent to each other, in such a way that two adjacent construction boxes  48  have a common side wall  62 . The common side wall  62  may, for example, separate the two (respective) adjacent construction spaces  44  from each other. The common side wall  62  may, for example, be removable/detachable so that two adjacent construction spaces  44  can be connected to form a larger construction space. In this case, a/the control device may be configured, for example, to synchronously control the construction platforms of the connected construction spaces  44 , for example so that the construction platforms always have the same height (in a z direction in  FIGS. 6 and 7 ). For example, it may be possible to connect more than two adjacent construction spaces  44  to form a common construction space. 
     The construction spaces  44  may, for example, each define an elongated construction field  46  and may be arranged in series one after the other, so that the construction fields  46  are aligned with their longitudinal axes one after the other or in extension of each other (see  FIGS. 6 and 7 ). The longitudinal axes of the construction fields  46  may, for example, be congruent. 
     In a plan view, the construction spaces  44  and the construction fields  46 , respectively, may have two long sides and two short sides, for example, and may be arranged, for example, adjacent to each other along a respective short side (see  FIGS. 6 and 7 ). 
     The rail system  36  may, for example, comprise one or more rails. In  FIGS. 6 and 7 , for example, a rail system with two rails is shown. The longitudinal axis (axes) of the one or more rails may, for example, extend (substantially) parallel to the long sides of the construction spaces  44  and/or (substantially) parallel to the longitudinal axes of the construction spaces  46 . 
     The print head coater module  10  may, for example, be displaceable along the rail system  36  (for example along the one or more rails) in a direction that is (substantially) parallel to the long sides of the construction spaces  44  and/or (substantially) parallel to the longitudinal axes of the construction fields  46  (see  FIGS. 6 and 7 ). 
     The 3D-printer according to the third and/or fourth embodiment may, for example, comprise a channel structure  50  which extends underneath the plurality of construction boxes  48 , wherein the construction boxes  48  may, for example, be configured to discharge loose particulate material downwards (in the z direction in  FIGS. 6 and 7 ) into the channel structure  50 . The channel structure  50  may for example optionally be inclined and/or may comprise a particulate material conveyor device (for example a conveyor belt), for example to discharge the loose particulate material. 
     The 3D-printer  42  according to the third and/or fourth embodiment may, for example, comprise a first and a second turning device (not shown in the Figures), arranged at a/the first longitudinal end  52  and at a/the second longitudinal end  54  of the series of construction spaces  44  and construction boxes  48 , respectively, and configured to turn the print head coater module  10  so that after a first journey over the construction spaces  44  and/or construction boxes  48 , the print head coater module  10  is ready for a second journey over the construction spaces  44  and/or construction boxes  48  in the reverse direction. Such a turning device is particularly suitable for the 3D printer  42  according to the third embodiment in which a print head coater module  10  according to the first embodiment is used (as shown in  FIG. 6 ). 
     The 3D printer  42  according to the third and/or fourth embodiment may, for example, comprise a control device (not shown in the Figures) which controls the print head coater module  10  in such a way that it coats and prints during a first journey over the construction spaces  44  and/or construction boxes  48  and performs an idle run during a second journey over the construction spaces  44  and/or construction boxes  48 , or that it coats during a first journey over the construction spaces  44  and/or construction boxes  48 , and prints during a second journey over the construction spaces  44  and/or construction boxes  48 , which is performed in an opposite direction to the direction of the first journey. A control device configured in this way is particularly suitable for the 3D printer  42  according to the third embodiment, in which a print head coater module  10  according to the first embodiment is used (as shown in  FIG. 6 ). 
     For example, the 3D printer  42  according the third and/or fourth embodiment may have a return path (not shown in the Figures) that connects a/the first longitudinal end  52  of the series of construction spaces  44  and/or construction boxes  48  with a/the second longitudinal end  54  of the series of construction spaces  44  and/or construction boxes  48 , to guide the print head coater module  10  back to the first longitudinal end  52  after a first travel over the construction spaces  44  and/or construction boxes  48  starting from the first longitudinal end towards the second longitudinal end  54 , during which the print head coater module  10  coats and prints. A control device configured in this way is particularly suitable for the 3D printer  42  of the third embodiment, in which a print head coater module  10  according to the first embodiment (as shown in  FIG. 6 ) is used. 
     For example, the 3D printer  42  according to the fourth embodiment may have a/the print head coater module  10  that is configured to be bidirectional to coat and print during both a first journey and a second journey (as shown in  FIG. 7 ). For example, the print head coater module  10 , which is configured to be bidirectional, may be configured as described above. The print head coater module  10 , which is configured to be bidirectional, may, for example, be the print head coater module  10  according to the second embodiment. For example, the print head coater module  10 , which is configured to be bidirectional, may comprise a print head  12  and two coaters  14 , each with a container  16  and a roller assembly  20 . For example, the print head coater module  10 , which is configured to be bidirectional, may comprise two print heads  12 , a container  16  and two roller assemblies  20 . 
     For example, the 3D printer  42  according to the third and/or fourth embodiment may comprise a tank  68  for a/the treatment agent (for example binder agent, for example binder). The tank  68  may be configured, for example, to fill the print head  12  (for example automatically, for example in a way controlled by a control device) with treatment agent, for example when the level of treatment agent in the print head  12  falls below a (pre)determined limit. 
     The 3D-printer  42  according to the third and/or fourth embodiment may, for example, comprise a tank  70  for a/the particulate material (for example sand, for example metal powder). The tank  70  may, for example, be configured to fill the container  16  with particulate material (for example automatically, for example in a way controlled by a/the control device), for example when the level of particulate material in the container  16  falls below a (pre)determined limit. 
     For example, the 3D printer  42  according to the third and/or fourth embodiment may be located in a room  72 . For example, the room  72  may have a floor  74  and walls  76 . For example, the room  72  may have an opening  78  (for example, a door) through which the room may be entered (for example by an operator, for example to perform maintenance on the print head coater module  10  and/or the 3D printer  42 ) and/or through which particulate material can be removed from the room  72  (for example by means of the channel structure  50 ). A crane  66  may be provided in the room  72 , for example to place and/or remove the print head coater module  10  on and/or from the rail system  36 , and/or to remove (for example lift out) the common/shared side walls  62 . In room  72 , for example, cameras  64  may be arranged, for example on the walls  76  of the room  72  and/or on the ceilings (not shown in the Figures) of the room  72 . The cameras  64  can be used, for example, to monitor or control a printing process of the 3D printer  42  placed in the room  72 .