Method and apparatus for manufacturing bodies using an additive manufacturing process

Abstract

A method for producing bodies using an additive manufacturing process in which solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) are applied in individual layers (3, 4) and selectively bonded with a binder material, wherein the binder material, in the form of binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k), in particular liquid binder particles, is selectively added to the solid particles, characterized in that one or more of the parameters material, size, arrangement, and orientation of individual solid particles are determined as a function of their location in the last applied layer (3) and / or a desired location-dependent distribution of one or more of these parameters is generated, wherein the location-dependently determined or generated parameters of the solid particles on the one hand and the target parameters of the binder particles on the other hand are applied to each other during their addition. to be voted on.

Description

[0001] The invention lies in the field of mechanics, materials science, and micromechanics. It is particularly advantageous, for example, in the production of components using additive manufacturing processes in the fields of mechanical engineering, automotive engineering, consumer products, medical technology, energy technology, and aviation, where special requirements are placed on the mechanical properties of the components.

[0002] From the state of the art, so-called layered construction processes for the production of three-dimensional bodies are known within additive manufacturing processes and especially in the so-called 3D printing processes, in which layers consisting of unconnected solid particles are stacked on top of each other and, at the points where the component is to be created, solid particles are connected to one another by a selectively added binder material.

[0003] The binder material is often printed onto the surfaces to be printed in a matrix of droplets. The aim is to penetrate the particulate material by the binder material in a predictable and locally limited manner, but preferably at the depth of the last applied layer.

[0004] With regard to known methods and devices, reference is made in this context, for example, to the disclosure in the documents US 2022 / 0 314 545 A1, JP 2015- 112 752 A or US 11 224 917 B1.

[0005] Against the background of the prior art, the object of the present invention is to provide a method and a device which make it possible to achieve the best possible controllable distribution of the binder material in a method of the type mentioned.

[0006] The problem is solved by the invention with the features of the independent patent claims. The subclaims present advantageous implementations of the solutions.

[0007] The invention thus relates to a method for producing bodies using an additive manufacturing process in which solid particles are applied in individual layers and selectively combined with a binder material, wherein the binder material in the form of binder particles, in particular liquid binder particles, is added to the solid particles in a targeted manner, wherein one or more of the parameters material, size, arrangement and orientation of the solid particles are determined depending on the location in the last applied layer and / or a desired location-dependent distribution of one or more of these parameters is generated, wherein the location-dependent determined or generated parameters of the solid particles on the one hand and the target parameters of the binder particles on their addition on the other hand are coordinated with one another.

[0008] The solid particles can be formed by pourable particles, such as molding sand, in any geometric shape, which can generally be geometrically regular or irregular, symmetrical or asymmetrical in shape and arrangement, and can be of uniform or irregular size and orientation. The size of the solid particles can, for example, range from a few micrometers to a few millimeters in diameter.

[0009] The solid particles are stacked one after the other in layers using a layer-by-layer construction process, with each layer containing a single layer, partial layer, or multiple layers of particles. After each layer is applied, a binder material in the form of binder particles, such as binder droplets, is selectively added locally to bond several solid particles together, thus forming a coherent body layer by layer. The unbonded solid particles are later removed.

[0010] It was found within the scope of the invention that the penetration of the layer of solid particles by the binder material in prior art processes often does not occur in the desired manner or depth. According to the invention, by coordinating the size and / or arrangement and / or orientation and / or material of the particles on the one hand and the target parameters of the binder particles upon their addition on the other hand, it is achieved that the binder particles reach the desired regions in the topology of the last added particle layer in a desired quantity or size. This makes it possible, for example, to achieve a desired penetration depth of the binder particles selectively or across the entire surface, and thus good penetration of the body to be produced.

[0011] Often, a specific size, arrangement, or orientation of solid particles or particle groups, for example, in the topmost layer(s) of a layer, obscures parts of the underlying layers in such a way that they cannot be reached by the added binder particles, or that the binder particles can only reach these underlying layers under certain conditions. The invention solves these problems by arranging and / or orienting the particles in an optimized manner, by determining the parameters of the solid particles, and / or by suitably controlling the target parameters of the added binder particles.

[0012] The target parameters of the binder particles can include, for example, the kinematic parameters such as the speed and the ejection or impact direction of the binder particles on the surface of the particle layer, or the material of the binder particles, their mass, the number of binder particles ejected consecutively onto the same location of the last applied layer of solid particles, and their size. For example, depending on the parameters of the solid particles in the topmost layer, the speed, ejection direction, and material of the binder particles can be variably controlled depending on the location, and / or the size of the binder particles, or the combination of material and size of the binder particles, or the combination of impact direction and size, or size and material.The material of the binder particles can be varied, for example, when using a liquid binder material by using a print head that can eject different liquids dropwise through different nozzles. Furthermore, the target parameters can include a swirl, for example, in the form of an angular momentum of the binder particles, or additional controllable parameters such as a specifically generated air flow or an electric or magnetic field that influences the trajectory of the binder particles.

[0013] The parameters of the solid particles in the last applied layer can be actively controlled in a variant of the process. For example, when applying a layer, gaps or grooves can be regularly left between the solid particles of the topmost layer or several upper layers of a layer, or they can be formed after application to provide access for the binder particles to the underlying layers at specific injection angles. This significantly improves the 3D penetration of several layers of a layer of solid particles by the binder particles and reduces the anisotropy in the component created by the process, which arises from incomplete penetration of a layer with the binder material in the direction of the layer sequence.It may also be useful, if the top layer contains solid particles made of several different materials or of different sizes, to use binder particles made of a different material in the vicinity of these solid particles, the arrangement of which can be determined or specifically generated, than in the other areas of the layer.

[0014] The arrangement of solid particles can be understood as all kinds of representations of the spatial coordinates of the individual particles, whereby in extreme cases, the spatial coordinates of each individual particle can be meant. In many cases, the arrangement of solid particles can also be understood as a set of structural parameters, such as a regular or average distance between neighboring parameters in one, two, or three spatial directions, or an offset of the individual particles in the direction perpendicular to the surface of the most recently added layer. Such parameters can also describe the spatial coordinates of groups, for example, rows or clusters of several solid particles, if the layers consist of such groups.

[0015] Particle orientation can be understood as the orientation of specific particle axes in space or, for example, in the case of completely irregularly shaped bodies, the angular position of individual particles around three independent spatial axes or the orientation of the axis of their greatest dimension in space. The orientation of particles or groups of particles can, for example, be advantageously described in polar coordinates. Useful subcombinations of actively designed or determined parameters of solid particles include the size and arrangement / positioning of the particles, or the material and arrangement, or the material, arrangement, and size, whereby the orientation can also be added in each case.

[0016] In one implementation of the method, it can be provided that the target parameters of the binder particles are controlled during their addition as a function of the location-dependently determined or generated parameters of the solid particles or, in the case that location-dependent parameters of the solid particles have been specifically generated, predetermined target parameters of the binder particles are applied for the location-dependently generated parameters when adding the binder particles.

[0017] Thus, in one case, a specific arrangement and / or orientation of the solid particles can be specifically created during layer build-up or after layer build-up, and then a suitable set of target parameters can be selected when adding the binder particles.

[0018] For example, during the layer build-up, grooves or gaps can be deliberately left open in the uppermost layer of solid particles or created after the layer has been built up. This can be done, for example, by combing the surface of the last layer applied with a rake-like tool or treating it with a needle roller. Particles of different types and / or sizes can also be applied one after the other when a layer is applied. This way, for example, the last-applied larger solid particles can create grooves between the previously applied smaller particles when they are poured or doctored on. Binder particles of a selected size can then be deliberately introduced into these grooves or gaps and moved towards the surface at a controllable angle and speed in order to reach the particles and interparticle spaces beneath the uppermost layer of solid particles.In another case, the size and / or arrangement and / or orientation of the solid particles can be taken as given and precisely determined to adjust one or more target parameters of the binder particles accordingly. This adjustment can be location-dependent, so that one or some or all of the target parameters are controlled location-dependently upon addition of the binder particles.

[0019] Exemplary subcombinations of the respective controlled target parameters can be the target location on the surface and the size / mass of the binder particles, in some cases also supplemented by the number of binder particles deposited at the same target location or the target location and the material of the binder particles or the target location, material and mass of the binder particles.

[0020] In a further possible implementation of the method, it can be provided that the binder particles are added in a targeted manner in liquid form by means of a jet printing process, wherein the material and / or the speed and / or the size or number of the individual binder particles and / or their direction of impact on the surface of the last layer applied are controlled, wherein the control of the said variables is carried out in particular by controlling a print head and / or by generating an air flow in the region of the last layer applied and / or by an electric or magnetic field.

[0021] The method according to the invention can also be carried out with solid or gel-like binder particles, in which case, in some cases, a binding effect can only be generated after the binder particles have been deposited in the layer by further action, such as irradiation or heat. However, the use with liquid binder particles in the form of droplets is particularly advantageous because the size, speed, and ejection direction of such droplets from a print head can be particularly well controlled. The amount of binder material deposited at a particular location on the surface can be controlled by varying the size and / or density of the binder particles or the number of binder particles ejected successively towards the same location on the surface.

[0022] The droplet trajectory can then be further directed by swirling the droplets and / or by a deliberately generated air stream. Such an air stream can be directed at the surface of the last applied layer of solid particles and also pass through this layer. For this purpose, a vacuum can be created at another location on the layer stack by air extraction, for example, so that air or a process gas is drawn into the stack at the surface.

[0023] The invention may further provide that the material and / or the size and / or arrangement and / or orientation of the solid particles on the surface of the last applied layer is determined by an imaging optical method and / or the location-dependent determination of a physical quantity by scanning the surface.

[0024] It can also be provided that the material and / or the size and / or arrangement and / or orientation of the solid particles on the surface of the last applied layer is determined by recording one or more optical images, in particular one or more camera images, in particular under a defined illumination, wherein in particular an infrared image, an ultraviolet image or a spectroscopic image of the surface of the last applied layer is additionally taken and evaluated.

[0025] For example, the surface of the layer stack can be illuminated and the size and / or arrangement and / or orientation of the solid particles on the surface of the last applied layer can be determined by optical scanning or a photographic image. Multiple camera images from different positions and / or under different illumination directions can be linked together to determine the surface structure in three dimensions. The illumination direction and / or an optical spectrum of the illumination can be matched to the direction of the image acquisition to achieve good contrast results. The photograph can then be further processed using automated image processing to determine the surface shape.However, the surface can also be scanned with a probe that measures the 3D shape capacitively, inductively, or in some other location-dependent way, thus enabling the determination of the topology. To determine the material of solid particles, for example, their color can be recorded, or an infrared or UV spectrum, or a fluorescence spectrum, can be recorded.

[0026] In a further embodiment of the invention, as already described above, it can be provided that the solid particles of each individual layer are applied in a desired arrangement and / or orientation.

[0027] Alternatively or additionally, it may be provided that the arrangement and / or orientation of the solid particles of each individual layer is influenced after application in order to achieve a desired arrangement and / or orientation. In this context, the arrangement of the solid particles should also be understood to mean, among other things, that a specific positioning of solid particles of different types, sizes, or materials relative to one another is created or determined.

[0028] It can be provided that the arrangement and / or orientation of the solid particles is influenced during application and / or after application by mechanical processing, exposure to electrical and / or magnetic fields, exposure to mechanical vibrations on the applied layers or exposure to sound waves.

[0029] During the application of solid particles, their structure, arrangement, and orientation on the layer surface can be controlled, for example, by appropriately controlling the application process, such as a pouring or trickling process. This can be achieved, for example, by air currents during application, trickling the solid particles through a sieve or a plate with structured openings, wiping across the surface, or by imprinting the surface with a structured stamp or pincushion. Furthermore, electric and magnetic fields generated in the region of the trajectory of the solid particles or in the region of the layer surface can produce specific geometric or topological structures of the solid particles.The same can be achieved with sound waves or ultrasonic waves, even superimposed from different sources, or through specific mechanical vibrations in the area of ​​the last added layer of solid particles. Vibrations can then either move larger solid particles between smaller particles to create grooves, or create standing waves with corresponding patterns that can lead to a geometric or topological ordering or structuring of the solid particles.

[0030] A particular embodiment of the method may also provide that during the addition of the binder particles, in each case in a partial section of the surface of the last applied layer of solid particles in which binder particles are to be added, the material and / or the size and / or arrangement and / or orientation of the solid particles are determined, the target parameters of the binder particles for this partial section are determined and are controlled location-dependently when the binder particles are added.

[0031] The 3-dimensional shape of the surface of the last added layer of solid particles can thus be recorded using a probe or a camera in the area in which binder particles are immediately added. The kinematic parameters and / or other target parameters of the binder particles, such as the mass, number, and material of the binder particles, or other target parameters discussed in this text, can then be directly controlled based on the determined surface shape. For this purpose, a probe or a microcamera, for example, can be directly connected to a print head. Then, after calibrating the relative position of the probe or camera to the print head, a determined set of parameters for the solid particles can be very quickly converted into target parameters for the binder particles on a location-dependent basis or implemented using an electronic circuit.In this method, in order to accelerate the determination of layer parameters and the determination and control of target parameters, the determined layer parameters could be limited to the arrangement of the solid particles and the controlled target parameters could be limited to the target locations of the binder particles.

[0032] The invention relates not only to a method of the type described above but also to a device for producing bodies using an additive manufacturing process, with a layering device designed to apply solid particles in individual layers, and with a jet device for the targeted addition of a binding material in the form of binder particles, in particular liquid binder particles,wherein the device comprises a determination device for determining the material parameters and / or the size and / or arrangement and / or orientation of the solid particles depending on the location in the last applied layer and / or a structuring device for generating the desired location-dependent distribution of one or more of the said parameters of the solid particles as well as a control device for controlling the target parameters of the binder particles during their addition depending on the location-dependent determined parameter(s) of the solid particles.

[0033] The invention is shown below with reference to figures of a drawing and explained below.

[0034] It shows: Fig. 1: a uniform distribution of binder particles over a layer of solid particles, Fig. 2: the distribution of a liquid binder material due to uniform distribution of the binder particles on the layer surface according to the state of the art, Fig. 3: schematically the determination of parameters of the solid particles of a layer, Fig. 4: a one-dimensional representation of a parameter curve of the solid particles of a layer and a corresponding curve of a target parameter of binder particles, Fig. 5: a location-dependent distribution of binder particles over a layer with different impact directions on the surface, Fig. 6: schematically a device for determining the parameter distribution of solid particles in a layer and for controlling target parameters of the binder particles, Fig. 7: a structuring device for generating geometric structures of the solid particles in a layer, Fig. 8: a vacuum device for generating an air flow to direct binder particles, Fig. 9: a device for generating electric fields for guiding binder particles and Fig. 10 a device for determining the parameters of solid particles including their orientation in a layer.

[0035] The Fig. 1 shows a schematic view of two layers 3, 4 of solid particles 1a to 1i stacked one above the other. Such solid particles can be, for example, molding sand particles that are processed into cores or casting molds for metal casting or other casting processes. For this purpose, the solid particles can be stacked layer by layer and, after each new layer has been applied, can be selectively bonded to one another in certain areas using a binder material in order to create a variety of geometric shapes. A furan resin, for example, can be used as a binder material in casting molds, although resins or other adhesive materials that can be moved in the form of liquid, gel-like, or solid particles can generally be used for this or other applications.

[0036] The binder particles are in the Fig. 1 above the surface 3a of the last applied layer 3 in the form of similar and equally sized particles 2a to 2i, which are also evenly distributed over the surface 3a.

[0037] Since the solid particles 1a to 1i in many cases do not show a completely homogeneous distribution in their distribution structure or their individual properties, the binder material often does not penetrate the last applied layer 3 evenly. This is shown schematically and exemplarily in the Fig. 2 by the hatched coatings of the solid particles with the liquid binder material.

[0038] In the Fig. 1 it is evident that the density of the solid particles 1a to 1i in the area of ​​the surface 3a varies depending on the location. The dashed surface 3a in this context is understood to be a macroscopic contour of the last applied layer 3. In the one-dimensional representation, gaps arise, for example, between the particles 1a and 1b, between the particles 1d and 1e and between the particles 1f and 1g. A sufficient amount of binder material should be introduced into these gaps, which then reaches the lower layers, for example to the particles 1c, 1i and 1h. In addition to the varying density distribution of the particles, which in the Fig. 1 and Fig. 2, the size, the material of the particles as well as the distance of the particles in the uppermost layer to the surface 3a in the z-direction can also vary.

[0039] For example, particle 1a reaches directly to surface 3a, shown as a dashed line, while particle 1f lies a little way behind or below the surface.

[0040] In the Fig. Figure 3 schematically shows an arrangement that enables the determination of parameters of the solid particles 1a to 1i. Arrows 8 and 9 represent two illumination directions in which the surface 3a is illuminated in order to take two photographs of the surface 3a one after the other with the camera 7. Additionally or alternatively, the orientation of the camera can be varied during the recording. By linking the images in an image processing system, a high-contrast image can be generated that also contains 3-dimensional information and, in addition to the size of the particles 1a to 1i, enables the 3-dimensional determination of the position of the individual particles and, if they have an irregular shape, also the determination of their orientation.In addition, information about the material of the individual particles can be obtained through infrared illumination and imaging, color imaging, fluorescence spectroscopy, or similar methods.

[0041] In the Fig. 4, for example, represents the position of the adjacent particles in the z-direction in a single dimension by the relief curve 5 as the only determined parameter of the solid particles. The minima of the relief curve 5 in the regions 5a, 5b, and 5c indicate the areas in which the solid particles are at a particularly large distance from the surface contour of surface 3a, represented as a straight line, and thus in which gaps or recesses are present in surface 3a into which binder particles should be introduced.

[0042] The function graph 6 shows the amount of binder material, for example the size, number and / or density of the binder particles, as the only target parameter to be controlled, which can result from the relief function 5. The calculated location-dependent distribution of the binder amount over the surface 3a in the example shown depends only on the one parameter of the position of the individual particles in the Z direction, but when calculating the distribution of the binder amount, any other of the parameters material, size, arrangement and orientation of the solid particles depending on the location in the last applied layer can be taken into account, or even a sub-combination of these parameters.

[0043] Represented in two dimensions, this results in a matrix of the quantity distribution of the binder material over the surface, which is converted into corresponding target parameters of the binder particles.

[0044] In addition to the pure quantity distribution of the binder material, any of the other target parameters of the binder particles can also be determined depending on the parameters of the solid particles in a location-dependent manner using a mapping function, a matrix or a multidimensional tensor.

[0045] An example is the Fig. 5 shows a variable distribution of size, number, density and direction of ejection of the binder particles over the surface 3a sequentially at the same location.

[0046] The binder particles 2i and 2j are particularly large. Instead of a single large binder particle, several smaller binder particles can also be deposited consecutively at the same location on the surface 3a. This is exemplified by the particle groups 2b and 2c, each consisting of sequences of three binder particles.

[0047] The ejection directions of the binder particles, indicated by arrows, are designed in such a way that, for example, the movement directions of the binder particles 2e, 2f, 2g are directed together towards the gap between the particles 1d and 1f, while the movement directions of the binder particles 2h, 2i, 2j, 2k are controlled in such a way that they are directed together towards the gap between the solid particles 1f and 1g. This achieves, as shown in the Fig. 5, sufficient binder material penetrates deep into layer 3 to achieve reliable binding of the underlying solid particles. For clarity, the binder material is shown hatched in the areas of the layer where it arrives after applying the target parameters of the binder particles in the form of the illustrated movement directions.

[0048] The invention and the method according to the invention can be used particularly advantageously for components with special manufacturing process requirements. For example, the maximum layer thickness with which a component can be produced is often limited by the imperfect penetration of binder particles. The described application allows binder particles to be selectively introduced into the layer at a particularly deep level, thus creating a strong layer bond even with high layer thicknesses.

[0049] Another application that particularly benefits from the invention is printing with particle-charged inks. In these, solid particles are suspended in a liquid binder. This means that the binder particles in such an application consist of a combination or mixture of a liquid material and solid particles. For example, the binder particles can be designed as droplets of a liquid in which solid particles are floating, or as solid particles wetted with a liquid. Binder particles are also conceivable that consist of droplets of a first liquid within a larger droplet of a second liquid. The process makes it possible to specifically place the liquid components and / or the solid particles in the powder bed and to control the material composition.

[0050] In the Fig. Figure 6 schematically shows aspects of a device for carrying out the described method. Symbolically, a layer device 16 is shown, which serves to add solid particles to a layer, wherein a location-dependent structure or distribution of the particles can be created already during the addition of the solid particles. Furthermore, a camera 7 is shown as part of a determination device for determining the parameters of the solid particles, as well as a processing device 18, which can, for example, contain optical image processing for image analysis. In the processing device 18, the analysis of the parameters of the solid particles can then be converted into a distribution function for the target parameters of the binder particles. The target parameters can be passed on to a control device 19, which controls the target parameters of the binder particles in a location-dependent manner during addition to layer 3.A jet device 10 in the form of a print head, for example, a thermal or piezo print head, can convert the target parameters into a printing process. Arrows 11, 12 symbolically indicate the directions of movement of the print head.

[0051] The Fig. Figure 7 shows a processing step in which, after the application of layer 3, a structure in the form of recesses or gaps can be introduced into the surface of the layer using a needle roller 13. Alternatively or additionally, a structure can also be introduced by an embossing die or by applying sound or ultrasonic waves from a transducer 14 during or after the application of layer 3, or by directly inducing vibrations, as symbolically represented by the pulse excitation device 15.

[0052] In the Fig. Figure 8 shows, as a potential aspect of the described method, that the layer stack is introduced into a container 20, from which air or a process gas can be extracted at the bottom to create a negative pressure in the layer stack. The negative pressure ensures that, in the area of ​​the surface 3a of layer 3, the gas flows through the free spaces between the solid particles into the layer stack, entraining and thus directing the ejected binder particles. The gas flow distribution at the surface 3a is represented by the arrows 17a, 17b, 17c, 17d, 17e, which are directed differently depending on the location. In the area below the layer stack, the arrows 21a, 21b, 21c indicate the extraction of gas.

[0053] In the Fig. Figure 9 illustrates the application of a voltage between a print head and the particles of the layers on a layer stack comprising layers 3 and 4, thereby generating an electric field to influence the ejection motion of the binder particles. The electric field can also be suitably configured by various electrodes in the area in front of surface 3a to achieve location-dependent steering of the binder particles as they are added to layer 3.

[0054] In the Fig.Figure 10 shows, by way of example, another variant of an inhomogeneous composition of the solid particles of a layer 3, in which some of the particles have a different shape and size than others. In this specific case, particles 1d and 1f, in contrast to the other spherical particles, are larger and elongated, shaped like rotational ellipsoids. The aforementioned particles 1d, 1f have longitudinal axes 22, 23, the position and orientation of which can be determined using the methods described above and taken into account when specifying the target parameters of the binder particles.

[0055] By considering a selection of parameters or all parameters of the solid particles in the last applied layer when determining the target parameters of binder particles during their addition, a well-controllable distribution of the binder material can be achieved within the layers of the layer stack and thus in the resulting 3-dimensional body. This allows for uniform penetration of the binder material and reduced anisotropy of the body.

Claims

[1] Method for producing bodies using an additive manufacturing process, in which solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) are applied in individual layers (3, 4) and selectively bonded with a binder material, wherein the binder material in the form of binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k), in particular liquid binder particles, is added to the solid particles in a targeted manner, characterized by that one or more of the parameters material, size, arrangement and orientation of individual solid particles are determined as a function of the location in the last applied layer (3) and / or a desired location-dependent distribution of one or more of these parameters is generated, wherein the location-dependent determined or generated parameters of the solid particles on the one hand and the target parameters of the binder particles on their addition on the other hand are coordinated with one another. [2] Method according to claim 1, characterized bythat the target parameters of the binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k) are controlled during their addition as a function of the location-dependently determined or generated parameters of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) or, in the case that location-dependent parameters of the solid particles have been specifically generated, predetermined target parameters of the binder particles are applied for the location-dependently generated parameters when the binder particles are added. [3] Method according to claim 1 or 2, characterized bythat the binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k) are added in a targeted manner in liquid form by means of a jet printing process, wherein the material and / or the speed and / or the size or number of the individual binder particles and / or their direction of impact on the surface (3a) of the last layer (3) applied are controlled, wherein the control of the said variables takes place in particular by controlling a print head (10) and / or by generating an air flow (17a, 17b, 17c, 17d, 17e) in the region of the last layer (3) applied and / or by an electric or magnetic field. [4] Method according to claim 1, 2 or 3, characterized bythat the material and / or the size and / or arrangement and / or orientation of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) on the surface (3a) of the last applied layer (3) is determined by an imaging optical method and / or the location-dependent determination of a physical quantity by scanning the surface. [5] Method according to claim 4 characterized bythat the material and / or the size and / or arrangement and / or orientation of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) on the surface (3a) of the last applied layer (3) is determined by recording one or more optical images, in particular one or more camera images, in particular under a defined illumination, wherein in particular an infrared image, an ultraviolet image or a spectroscopic image of the surface of the last applied layer is additionally taken and evaluated. [6] Method according to one of claims 1 to 5, characterized by that the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) of each individual layer (3, 4) are applied in a desired arrangement and / or orientation. [7] Method according to one of claims 1 to 6, characterized bythat the arrangement and / or orientation of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) of each individual layer (3, 4) is influenced after application in order to achieve a desired arrangement and / or orientation. [8] Method according to one of claims 1 to 7, characterized by that the arrangement and / or orientation of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) is influenced during application and / or after application by mechanical processing, exposure to electric and / or magnetic fields, exposure to mechanical vibrations on the applied layers or exposure to sound waves. [9] Method according to one of claims 1 to 8, characterized bythat during the addition of the binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k) in each case in a partial section of the surface of the last applied layer of solid particles in which binder particles are to be added, the material and / or the size and / or arrangement and / or orientation of the individual solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) are determined, the target parameters of the binder particles for this partial section are determined and are controlled in a location-dependent manner when the binder particles are added. [10] Device for producing bodies using an additive manufacturing process, comprising a layer device (16) which is designed to apply solid particles (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j, 1k, 1l) in individual layers (3, 4), and comprising a jet device (10) for the targeted addition of a binding material in the form of binder particles (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k), in particular liquid binder particles, characterized bythat the device comprises a determination device (7, 18) for determining the material parameters and / or the size and / or arrangement and / or orientation of individual solid particles as a function of the location in the last layer applied and / or a structuring device (13, 14, 15) for generating the desired location-dependent distribution of one or more of the said parameters of the solid particles and a control device (19) for controlling the target parameters of the binder particles during their addition as a function of the location-dependent determined parameter(s) of the individual solid particles.

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