Arrangement and method for applying particulate build material in a 3D printer

Abstract

Arrangement (1) for applying particulate building material (2) in a 3D printer, comprising a funnel-shaped storage container (3) for storing a particulate building material (2), which has an opening (4) aligned with a construction field (11), characterized in that a band-shaped blocking means (5) forming an opening slot (6) is arranged at the opening (4), wherein the band-shaped blocking means (5) is fixedly arranged on a first side wall (7) or a second side wall (8) of the funnel-shaped storage container (3), that at least one porous gas outlet means (9) is arranged on a side wall (7, 8) of the funnel-shaped storage container (3) or on the blocking means (5), and that a ventilation gap (19) is arranged between the blocking means (5) and the second side wall (8).

Description

[0001] The invention relates to an arrangement for applying particulate building material in a 3D printer, comprising a funnel-shaped storage container for storing a particulate building material, which has an opening aligned with a construction field.

[0002] The invention also relates to a method for applying particulate building material in a 3D printer, wherein the particulate building material is applied layer by layer to the building field from a funnel-shaped storage container having an opening in the direction of a building field.

[0003] It is known to use 3D printing or a 3D printing process to produce individual or series-produced components, workpieces, or molds. In such printing processes, three-dimensional components or workpieces are manufactured layer by layer.

[0004] The structure is computer-controlled and constructed from one or more liquid or solid materials according to specified dimensions and shapes. Specifications for the components or workpieces to be printed can be provided, for example, by computer-aided design (CAD) systems.

[0005] When printing 3D structures or 3D components, physical or chemical curing processes or a melting process take place. Plastics, synthetic resins, ceramics, and metals are used as materials for such 3D printing processes.

[0006] When implementing 3D printing processes, various manufacturing processes are known.

[0007] However, several of these procedures include the following exemplary procedural steps: • Partial or full-surface application of particulate building material, also referred to as particulate material, to a so-called building field in order to form a layer of unconsolidated particulate material; • Selective solidification of the applied layer of unconsolidated particulate building material in predetermined partial areas, for example by selective compaction, printing or application of treatment agents, such as a binder or use of laser; • Repetition of the previous process steps in another layer level to build up the component or workpiece layer by layer. For this purpose, the component or workpiece, which is being built up or printed layer by layer on the build area, is lowered with the build area by one layer level or layer thickness, or the 3D printing device is raised by one layer level or layer thickness relative to the build area before a new layer is applied partially or completely. • Subsequent removal of loose, unconsolidated particulate construction material surrounding the manufactured component or workpiece.

[0008] Various methods for producing a 3D structure or for applying particulate building material to a building field to create a 3D structure are known from the prior art.

[0009] From DE 10 2005 022 308 A1 a coater and a method for applying powdered layers in a device for producing a three-dimensional object by solidifying layers of a powdered material at the locations corresponding to the respective cross-section of the object are known.

[0010] The problem to be solved is to provide a device and a method for producing a three-dimensional object by solidifying layers of a powdered building material, with which the construction time for the three-dimensional object can be shortened.

[0011] For this purpose, the device comprises a coater that can be moved across a build area for applying layers of powdered building material to the build area. The coater is designed with a rigid blade that is rigidly connected to the coater. To preheat the powdered building material, the coater is equipped with a heating device that is at least partially integrated into the coater. This makes it possible to preheat the powder during or before application as a layer, thus shortening the overall construction time for the three-dimensional object.

[0012] From DE 10 2016 202 696 A1 a device for the additive production of three-dimensional components is known, in which a powder bed is successively built up layer by layer and each individual layer is influenced with a two-dimensionally deflectable energy beam in such a way that a locally defined solidification of the powdery material used is achieved by sintering or temporary melting, with which the powder bed is formed.

[0013] The aim is to reduce the manufacturing costs of this additive manufacturing process, which is achieved primarily by enabling the use of cost-effective powdered materials with lower production and storage requirements. Furthermore, it should be possible to process powders with smaller grain sizes, thus achieving lower surface roughness.

[0014] To form the individual layers made of powdered material with a constant, predeterminable layer thickness, at least one coating element is movable from a reservoir for the powdered material in an axial direction parallel to and at a predeterminable distance from the surface of a powder bed carrier in which the powder bed is successively received with the individual layers formed from the powdered material. The at least one coating element can be set into vibration during the movement to form a respective layer and / or the powder bed carrier. Alone or in addition to this, a gas flow can be directed through or onto the powdered material, the entire respective layer and / or the entire powder bed through the at least one coating element and / or the powder bed carrier.

[0015] WO 2016 / 095888 A1 discloses a method for producing three-dimensional molded parts using layered construction technology, whereby the moisture content of the building material mixture can be controlled.

[0016] The aim is to provide a process and a material system with which consistent material properties, in particular the flow properties of the building material, can be ensured during the construction process.

[0017] Therefore, it is envisaged that the particulate building material is applied to a construction site in a defined layer thickness using a coater. Furthermore, binder liquid is selectively applied to the building material via a print head, wherein the binder liquid is polymerized by means of at least one activator introduced into the sand. It is also envisaged that the construction site is lowered by the layer thickness or the coater is raised by one layer thickness, and these steps are repeated until the desired molded part is produced. Agents are or are introduced into the building material, the binder liquid, and / or the activator to control the moisture content of the building material mixture.

[0018] In this process, the moisture content in the sand is controlled. In particular, the water and liquid content are regulated or at least stabilized. This is intended to ensure essentially consistent chemical and physical properties during the production of the three-dimensional molded parts.

[0019] DE 10 2004 008 168 A1 relates to a method and a device for applying fluids, in particular particulate material, to an area to be coated, which enables controlled dosing and application of any desired, and thus also fine and / or highly free-flowing, powders. To achieve this, the device comprises a leveling element and, as seen in the forward direction of movement of the leveling element, a metering device by means of which fluid is applied to the area to be coated, and a blade is movable over the applied fluid, wherein the metering device is provided with an opening and can oscillate. It is further disclosed that an opening is provided such that, when the metering system is at a standstill, it is closed by the formation of a cone of fluid in the opening.

[0020] WO 2008 / 055615 A1 discloses a coater for applying powdered layers in a device for producing a three-dimensional object by solidifying layers of a powdered material. The aim is to provide a device and a method that enable more homogeneous powder application in a method for producing a three-dimensional object. To achieve this, a coater is provided which has a device for fluidizing the powdered material with a gas supplied to the coater. Also disclosed is a device for controlling and / or regulating the pressure and / or volume flow of the gas, and the powdered material is fluidized in the coater by means of a supplied gas.

[0021] The disadvantages of this known state of the art are that, for example, vibration-generating components are required to dispense the particulate building material in conjunction with a storage container, which are complex and mechanically vulnerable.

[0022] Likewise, controlling the quantity to be dispensed from the storage container for the current and defined layer thickness of the particulate building material is complex.

[0023] The object of the invention is to provide an arrangement and a method for applying particulate building material in a 3D printer, whereby a uniform application of the particulate building material on a construction field of a 3D printer is achieved and the control and effort in the production of the arrangement are reduced.

[0024] The problem is solved by an arrangement having the features according to claim 1 of the independent claims. Further developments are specified in the dependent claims 2 to 5.

[0025] The problem is also solved by a method having the features according to claim 6 of the independent claims. Further developments are specified in dependent claims 7 to 9.

[0026] The invention provides that in the arrangement for applying particulate build material in a 3D printer, which is also referred to simply as a coater below, a funnel-shaped storage container is used to store the particulate build material. This funnel-shaped storage container is designed as a longitudinally extended funnel-shaped storage container and is arranged above the build area of ​​a 3D printer such that its opening or outlet for the particulate build material is aligned in the direction of the build area.

[0027] An elongated storage container is a storage container whose length is a multiple of its width.

[0028] An elongated or band-shaped blocking means is arranged along the opening of the longitudinally extended, funnel-shaped storage container, wherein the band-shaped blocking means is fixedly arranged on a first side wall or a second side wall of the funnel-shaped storage container. This blocking means is designed and dimensioned such that an opening slot is formed through which the particulate building material cannot, or cannot significantly, escape through the opening slot toward the construction field when the storage container is normally filled. The arrangement of the blocking means reduces the size of the opening of the storage container, thus reducing it to merely an opening slot. The blocking means can, for example, be a strip- or band-shaped metal sheet.

[0029] A blade is positioned a short distance in front of the opening slot, onto which the particulate building material trickles in the event that a small amount of the particulate building material should escape. This small amount of escaping particulate building material forms a blocking cone on the blade, thus preventing further building material from escaping. This is possible because the particulate building material stored in the funnel-shaped storage container tends to form so-called pouring bridges and thus a blocking cone in front of the opening slot.

[0030] It is intended to arrange a porous gas outlet means on at least one longitudinally extending side wall of the funnel-shaped storage container, and to arrange a ventilation gap between the blocking means and the second side wall. Such a porous gas outlet means has a gas connection and a porous, air-permeable material. A gas, such as air, which is introduced from outside the storage container via the gas connection into the porous gas outlet means, can flow through the porous material and thus enter the storage container. The gas exits the porous gas outlet means distributed over the entire surface of the porous material. Such air escape can be compared, for example, to the air stones used in aquariums.

[0031] The openings or pores of this air-permeable material are preferably smaller than the grain size of the particulate building material. Thus, the particulate building material cannot penetrate the porous gas venting medium.

[0032] It is also provided that a porous gas outlet means can be arranged on the band-shaped barrier means. The arrangement of a porous gas outlet means can be carried out alone or together with the arrangement of a porous gas outlet means on a longitudinally extending side wall of the funnel-shaped storage container.

[0033] The porous gas outlet means is arranged in a region of the elongated side wall or in the region of the band-shaped blocking means such that the smooth inner surface of the funnel-shaped storage container or the blocking means is not disturbed or influenced. The funnel-shaped storage container thus remains flat on its inner surface even when the porous gas outlet means according to the invention is installed. The same applies to the blocking means, which can be implemented, for example, using a blocking plate. This ensures, on the one hand, the functionality of the storage container for applying particulate building material to a construction site and, on the other hand, prevents the particulate building material from getting caught on an unevenness on the inner side of the storage container or the blocking means, thus preventing disruptions when applying particulate building material to a construction site.

[0034] It is also provided to arrange a plurality of porous gas outlet means on a side wall of the storage container. These plurality of porous gas outlet means can be arranged at equal distances from one another and / or at equal distances from the opening slot on a longitudinally extending side wall of the storage container.

[0035] Alternatively, several porous gas outlets can be arranged on both longitudinal side walls of the storage container. Furthermore, several porous gas outlets can be arranged on the barrier. In a further variant, several porous gas outlets are arranged on both a side wall of the storage container and on the barrier.

[0036] It is also intended to arrange one or more porous gas outlet means opposite one another on the longitudinal side walls of the storage container or on one side of the storage container and on the blocking means.

[0037] The porous gas outlet means(s) are arranged near the outlet opening or opening slot. With such an arrangement of the porous gas outlet means in the region of the narrowest point of the elongated funnel-shaped storage container, the effect of the porous gas outlet means on fluidizing the particulate building material is optimal.

[0038] The porous gas outlet means are provided with a circular, oval, or rectangular gas outlet surface. In a particular form, the porous gas outlet means can have an elongated rectangular gas outlet surface, the length of which is a multiple of the width of the gas outlet surface. In this embodiment, these elongated or strip-shaped porous gas outlet means can be arranged parallel to the blocking means or the opening slot.

[0039] In the event that no gas is introduced into the porous gas outlet means(s), the particulate building material cannot escape through the narrow opening slot formed by the blocking means.

[0040] If a gas such as air is introduced into the porous gas outlet(s), the gas introduced into the reservoir fluidizes the particulate build material, causing it to exit the reservoir through the opening slot. The escaping particulate build material thus reaches the build area of ​​the 3D printer.

[0041] Thus, an assembly and method for applying particulate build material in a 3D printer can be provided that does not require any moving or vibrating mechanical components or their drives. Furthermore, no heating elements are required to achieve fluidization of the particulate build material.

[0042] The intention is to distribute the emerging particulate build material in a layer over the build area and to process it in the usual way, i.e., to selectively solidify it in predetermined sub-areas. This solidification can be carried out in a manner known from the prior art, such as using a laser. This description does not impose any restrictions on this manufacturing step for generating a 3D model or a 3D structure in a 3D printer. This method step will not be discussed further below, as it is not relevant to the present arrangement or method for applying particulate build material in a 3D printer.

[0043] The gas used is air, reactive gases, or inert gases. Nitrogen and all noble gases, for example, can be used as inert gases.

[0044] It is also provided that the gas pressure is controlled. The amount of gas escaping from the porous gas outlet influences the degree of fluidization of the particulate building material and thus the amount of building material passing through the opening slot. Thus, according to the invention, the amount of particulate building material escaping from the reservoir is controlled by means of the gas pressure, adjusted to the position and application speed.

[0045] According to the invention, it is intended to operate with a periodically changing gas pressure. The invention operates with a pulsating gas pressure. In this case, the mean value of this gas pressure can be the variable to be controlled for the gas pressure and thus for the amount of escaping particulate building material.

[0046] Any arrangements and methods known from the prior art can be used to generate gas pressure. The present invention is not limited to this. Such solutions are known to those skilled in the art, so this area will not be discussed further.

[0047] To control the amount of escaping particulate build material, sensors are provided and positioned outside the storage container. These sensors, such as ultrasonic, infrared, laser distance, or capacitive sensors, are aligned such that they can detect the amount of escaping particulate build material. Such a sensor can be arranged, for example, on an outer side of a longitudinally extended side wall of the storage container or on an outer side of the barrier. This sensor is aligned such that it can detect the fluidized particulate build material that reaches the build area or build bed via the opening slot and the blade.

[0048] The above-described features and advantages of this invention will be better understood and appreciated after careful study of the following detailed description of the preferred, non-limiting exemplary embodiments of the invention with the accompanying drawings, which show: Fig. 1: an arrangement according to the invention for applying particulate building material in a 3D printer in a so-called rest state in which no particulate building material is applied, Fig. 2: an arrangement according to the invention for applying particulate building material in a 3D printer in an operating state in which particulate material is applied, Fig. 3: an arrangement according to the invention in a perspective view with a partial section of the elongated funnel-shaped storage container, Fig. 4: the arrangement according to the invention from the Fig. 3 with an enlarged section and Fig. 5: the positioning of the porous gas outlet means on the first side wall of the storage container.

[0049] The Fig. 1 shows an arrangement for applying particulate building material in a 3D printer in a so-called rest state, in which no particulate building material 2 is applied,

[0050] The arrangement 1 for applying particulate building material, which is referred to below as coater 1, has a funnel-shaped storage container 3 for storing the particulate building material 2. This funnel-shaped storage container 3 is designed to be longitudinally extended, with its length being a multiple of its width. This longitudinal extension of the funnel-shaped storage container 3 is in the Fig. 1 not shown, since the Fig. 1 shows a section through the storage container 3.

[0051] The storage container 3 has an opening 4 which is oriented towards the build area 11 of the 3D printer. As in the example of the Fig. 1, several layers of the particulate building material 2 have already been applied to the construction field 11 and form a construction bed 16. This construction bed 16 contains, in predetermined partial areas, selectively solidified and non-solidified particulate building material 2 for forming a 3D model to be printed.

[0052] Between the opening 4 of the funnel-shaped storage container 3 and the build bed 16, a blocking means 5 is arranged, through which the opening slot 6 is formed. The blocking means 5 is designed along the opening 4 in the form of a strip-shaped or band-shaped longitudinally extended sheet. The blocking means 5 can be arranged attached to a side wall 7 or 8 of the funnel-shaped storage container 3. In the illustration of the Fig. 1, the blocking means 5 forms the opening slot 6 on its lower side and a ventilation gap 19 on its upper side. The formation of such a ventilation gap 19 is not absolutely necessary according to the invention. The fastening of the blocking means 5 to a side wall 7 or 8 of the funnel-shaped storage container 3 and / or to the end faces of the funnel-shaped storage container 3 is Fig. 1 not shown.

[0053] For fastening the funnel-shaped storage container 3, a support arm 14 is provided, on which a blade 15 is arranged. This blade 15 is designed such that it has a surface parallel to the construction field 11 and is arranged at least partially in front of the opening slot 6. The partial arrangement of the blade 15 in front of the opening slot 6 prevents particulate building material 2 from accidentally reaching the construction field 11 or the construction bed 16, since a blocking cone 20 is formed between the blade 15 and the opening slot 6, closing the path. The blade 15 has a surface parallel to the construction field 11 in order to evenly distribute the particulate building material 2 into a new layer 17 after it has been deliberately applied to the construction field 11 or the construction bed 16, for example during the process of the coater 1 in the Fig. 1 to the left. This process is described in the Fig. 1 not yet shown.

[0054] The application of the particulate building material 2 to the construction area 11 or the construction bed 16 is achieved by fluidizing the particulate building material 2 in the region of the opening slot 6. For this purpose, at least one porous gas outlet 9 is provided in this region. Fig. 1, a first porous gas outlet means 9 is arranged on the right side wall 7 of the storage container 3 or on the support arm 14 and the right side wall 7.

[0055] This porous gas outlet means 9 has a gas-permeable porous material on its side facing the particulate building material 2. A gas connection 10 is arranged on the side facing away from the particulate building material 2. A gas with controllable gas pressure is generated by an external unit (not shown) and is fed to the porous gas outlet means 9, for example, via a line (not shown) connected to the gas connection 10. This gas exits the porous gas outlet means 9 through the gas-permeable porous material in the direction of the particulate building material 2 in a uniformly distributed manner and flows through the particulate building material 2. This escaping gas fluidizes the particulate building material 2, forming a region with fluidized particulate building material 12 within the particulate building material 2.

[0056] In an alternative, a porous gas outlet means 9 can be arranged on the second side wall 8 opposite the first side wall 7.

[0057] In a further alternative, porous gas outlet means 9 can be arranged on both side walls 7 and 8. The porous gas outlet means 9 can thus be arranged, for example, opposite one another or offset from one another on the side walls 7 and 8.

[0058] In the example of Fig. 1, the second side wall 8 is not completely parallel to the first side wall up to the opening slot 6. The extension of the second side wall 8 is formed in this example by the blocking means 5. In this embodiment, one or more porous gas outlet means 9 can be arranged on the blocking means 5. Such an arrangement of a porous gas outlet means 9 on the blocking means 5 is shown in Fig. 1. The porous gas outlet means 9 arranged on the blocking means 5 is shown in a different geometric shape, but also consists of an air-permeable porous material through which the gas flows out, and also has a gas connection 10, which is in the Fig. 1 is not shown.

[0059] The particulate building material 2 is present in the area of ​​the opening slot 6 as fluidized particulate building material 12 and can overcome the blocking cone 20 and exit the storage container 3 via the opening slot 6. In order to detect the amount of escaping particulate building material 12, it is provided to arrange at least one sensor 13. In the example of the Fig. 1, the sensor 13 is arranged on the blocking means 5 with a holder (not shown). Regardless of the arrangement of the sensor 13, it is important that the sensor 13 is aligned with its sensor beam 18 or its detection range toward the path of the particulate build material 12 to the build area 11 or the build bed 16. In one embodiment, the sensor beam 18 is aligned with the forming application cone 21.

[0060] In one embodiment, the coater 1 with all its components in the Fig. 1 can be moved in the directions shown by the upper double arrow above the construction field 11, while the construction field 11 is stationary.

[0061] In an alternative embodiment, the coater 1 is arranged stationary above the construction field 11, while the construction field 11 is designed to be movable below the coater 1 in the directions shown by the lower double arrow.

[0062] In the Fig. 2 shows the arrangement for applying particulate building material in a 3D printer in a state in which particulate building material is being applied.

[0063] The coater 1 assigns the already Fig. 1 described components.

[0064] While the coater 1 in the Fig. 1 in a resting state in which no particulate building material 2 is applied, the coater 1 is in the Fig. 2 during the application of particulate building material 2 to a build bed 16 located on a build area 11 of the 3D printer.

[0065] The build bed 16 was created, for example, by applying several new layers 17 in several previous work steps. Components of the 3D model to be created may already be formed in such a build bed 16. For this purpose, the particulate build material 2 has already been selectively solidified in predetermined sub-areas. Fig. 2 shows the application of a new layer 17 onto the existing build bed 16.

[0066] As already described, the particulate building material 2 is prevented from leaving the funnel-shaped storage container 3 by the forming blocking cone 20. To apply particulate building material 2, a gas is supplied to at least one porous gas outlet 9 via its gas connection 10, which gas exits through the porous material of the gas outlet 9 toward the particulate building material 2 and flows through it.

[0067] During this flow, the particulate building material 2 is fluidized and fluidized particulate building material 12 is created in the Fig. 2. The arrows in this area 12 represent the gas flowing through. In the example of Fig. 2, two porous gas outlet means 9 are arranged opposite one another. Thus, the gas flows into the particulate building material 2 from two sides, further enhancing the fluidizing effect of the particulate building material 2.

[0068] The thus fluidized particulate building material 2 is able to overcome the barrier cone 20 and can thus exit the funnel-shaped storage container 3 via the opening slot 6. The fluidized particulate building material 2 reaches the construction bed 16 via the blade 15 and forms an application cone 21 in front of the blade 15.

[0069] For example, by a horizontal movement of the coater 1 in the direction indicated by the arrow in the Fig. 2, the new layer 17 is applied to the build bed 16 in a predetermined thickness. To ensure a consistent thickness and density of the particulate build material 2 to be applied, it must be ensured that the application cone 21 in front of the blade 15 is of a correspondingly large size.

[0070] For this purpose, it is provided to detect the size of the application cone 21 by means of a sensor 13 and to control the size of the application cone 21 by means of a suitable control arrangement (not shown). Fig. 2, the sensor 13 is attached, for example, to the blocking means 5. Regardless of the type of attachment, the sensor 13 is aligned with its detection area toward the application cone 21. Such a sensor 13 can be, for example, an ultrasonic or infrared sensor. For example, an infrared sensor 13 is arranged with its sensor beam 18 aligned with the application cone 21.

[0071] To control the size of the application cone 21, the pressure of the gas fed into the porous gas outlet means 9 is varied depending on the sensor signal from the sensor 13. For example, by increasing the gas pressure, the fluidization of the particulate building material 2 can be enhanced or improved, as a result of which more fluidized particulate building material 12 can exit through the opening slot 6 and the size of the application cone 21 increases.

[0072] Alternatively, the fluidization of the particulate building material 2 can be reduced or worsened by means of a lower gas pressure, as a result of which less fluidized particulate building material 12 can escape through the opening slot 6 and the size of the application cone 21 decreases.

[0073] The applied quantity of the particulate building material 2 can therefore be controlled by controlling the gas pressure.

[0074] It can also be provided that the applied amount of particulate building material 2 is controlled by controlling an average gas pressure. In this variant, the gas pressure can be generated in a pulsating manner, for example, which makes it possible to improve fluidization.

[0075] The gas introduced into the particulate building material 2 via the porous gas outlet means 9 can, for example, in the special design of the coater 1 in the Fig. 2 escape via the ventilation 19. Alternatively, the gas can flow upwards in the funnel-shaped storage container 3 and thus leave it.

[0076] After the new layer 17 has been completely applied, the fluidization process of the particulate build material 2 can be stopped by shutting off the gas supply to the porous gas outlet elements 9. As a result, the blocking cone 20 will form in front of the opening slot 6 and prevent further particulate build material 2 from reaching the build bed 16.

[0077] The Fig. 3 shows an arrangement according to the invention in a perspective view with a partial section of the elongated funnel-shaped storage container 3.

[0078] The longitudinally extended funnel-shaped storage container 3 is in the Fig. 3 for a better understanding of the invention in a state filled with the particulate building material 2 in a perspective view. The funnel-shaped storage container 3 is in its right front area in the Fig. 3 and thus allows a view of the porous gas outlet element 9. This first porous gas outlet element 9, arranged on the first side wall 7 and the support arm 14, has a longitudinally extended surface through which the gas can escape. The gas connection 10 of the porous gas outlet element 9 was shown in the Fig. 3 shown in section. In the Fig. 3 also shows a second porous gas outlet element 9, which is arranged opposite the first porous gas outlet element 9 on the blocking means 5.

[0079] In the Fig. 4 is the arrangement according to the invention from the Fig. 3 with an enlarged detail. In this illustration, the first porous gas outlet means 9 arranged on the first side wall 7 is again shown with its longitudinally extended surface through which the gas can escape. Also in this illustration of the Fig. 4 shows the second porous gas outlet means 9 arranged opposite the first porous gas outlet means 9 on the blocking means 5.

[0080] For example, a gas is introduced into the first porous gas outlet 9 via its gas connection 10, which gas exits via the illustrated elongated surface of the porous gas outlet 9 and generates fluidized particulate building material 12. This fluidized particulate building material 12 passes through the opening slot 6 and forms the illustrated application cone 21.

[0081] By moving the coater 1 over the construction field 11 (not shown) or the construction bed 16 (shown) in the direction indicated by the arrow, the new layer 17 is created on the construction bed 16.

[0082] In the Fig. 4 also shows the sensors 13 with their sensor beams 18 that detect the size of the application cone 21. It is intended to arrange several sensors 13 next to one another in order to detect the size of the application cone 21 at several locations. In such an arrangement, it is possible to determine different sizes of the application cone 21 along the blade 15. By means of such a differentiated, area-specific testing of the sizes of the application cone 21, it is possible to carry out a differentiated, area-specific control of the porous gas outlet means 9 associated with this area. In this way, the quality of the application of the new layer 17 can be further improved.

[0083] It is clear that after applying a new layer 17, a selective solidification of the applied particulate material 2, depending on the 3D model to be printed, takes place using a method known from the prior art, such as the use of a laser.

[0084] In the Fig.Figure 5 shows the positioning of the porous gas outlet means 9 on the first side wall 7 of the storage container 3 in a view from the inside. In the lower region of the illustrated inside of the first side wall 7, several porous gas outlet means 9 are arranged. These porous gas outlet means 9 are designed as longitudinally extended porous gas outlet means 9 and are arranged in a row such that almost every area of ​​the opening slot 6 can be covered. This ensures that the particulate build material 2 can flow through every area of ​​the opening slot 6 by a gas flowing out of the porous gas outlet means 9 and can thus be fluidized. Thus, fluidized particulate build material 12 is generated in the entire area along the opening slot 6 (not shown) and can thus be applied to the build bed 16 in a uniformly distributed manner.The particulate building material 2 applied to the build bed 16 is removed by means of the blade 15 and forms a new layer 17. LIST OF REFERENCE SYMBOLS 1 Arrangement for applying particulate building material (coater) 2 particulate building material 3 funnel-shaped storage container 4 Opening the storage container 5 barriers (band-shaped chicane / barrier plate) 6 opening slot 7 first side wall of the storage container 8 second side wall of the storage container 9 porous gas escape agent 10 Gas connection 11 Construction site 12 fluidized particulate building material 13 Sensor 14 Support arm 15 blade 16 construction bed 17 new shift 18 Sensor beam 19 Ventilation gap 20 locking cones 21 application cones

Claims

[1] Arrangement (1) for applying particulate building material (2) in a 3D printer, comprising a funnel-shaped storage container (3) for storing a particulate building material (2), which has an opening (4) aligned with a construction field (11), characterized by that a band-shaped blocking means (5) forming an opening slot (6) is arranged at the opening (4), wherein the band-shaped blocking means (5) is fixedly arranged on a first side wall (7) or a second side wall (8) of the funnel-shaped storage container (3), that at least one porous gas outlet means (9) is arranged on a side wall (7, 8) of the funnel-shaped storage container (3) or on the blocking means (5), and that a ventilation gap (19) is arranged between the blocking means (5) and the second side wall (8). [2] Arrangement according to claim 1, characterized bythat the funnel-shaped storage container (3) is an elongated funnel-shaped storage container (3). [3] Arrangement according to claim 1 or 2, characterized by that several porous gas outlet means (9) are arranged on a side wall (7, 8) of the funnel-shaped storage container (3) or on the blocking means (5). [4] Arrangement according to one of claims 1 to 3, characterized by that a plurality of porous gas outlet means (9) are arranged both on a side wall (7, 8) of the funnel-shaped storage container (3) and on the blocking means (5). [5] Arrangement according to one of claims 1 to 4, characterized by that at least one sensor (13) is arranged in the region of the opening slot (6) outside the funnel-shaped storage container (3). [6] Method for applying particulate building material (2) in a 3D printer, wherein the particulate building material (2) is applied layer by layer to the building field (11) from a funnel-shaped storage container (3) having an opening (4) in the direction of a building field (11), characterized bythat an opening slot (6) is provided in front of the opening (4) by means of a band-shaped blocking means (5) provided fixedly on the first side wall (7) or second side wall (8), that at least one porous gas outlet means (9) is provided on a side wall (7, 8) of the funnel-shaped storage container (3) or on the blocking means (5), that an application of particulate building material (2) to the building field (11) is effected by applying a gas to the porous gas outlet means (9) which emerges from the porous gas outlet means (9) in the direction of the particulate building material (2) and fluidizes the particulate building material (2), that the amount of particulate building material (12) emerging through the opening slot (6) in the direction of the building field (11) is controlled by a pressure of the gas of the porous gas outlet means (9), wherein the Pressure of the gas is generated pulsatingly. [7] Method according to claim 6, characterized by that the gas emerging from the porous gas outlet means (9) provides a fluidized particulate building material (12) in the region of the opening slot (6), which material exits through the opening slot (6) in the direction of the building field (11). [8] Method according to claim 6 or 7, characterized by that the quantity of particulate building material (12) emerging through the opening slot (6) in the direction of the construction field (11) is measured by means of a sensor (13). [9] Method according to one of claims 6 to 8, characterized by that the gas is air, reactive gas or an inert gas.

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