Method and system for the additive manufacturing of objects

Abstract

Methods for the additive manufacturing of objects (12) comprising the following steps: • Providing a platform unit (16) with an active manufacturing area (10) of a 3D printing system for the production of at least one object (12) using an additive manufacturing process; • Producing at least one object (12) from individual layers of a first powdered material in the active production area (10) using at least a binder, by means of the 3D printing system, characterized in that the process comprises the following further steps: • Inserting at least one mesh structure (18) made of a second material different from the first material, which is arranged between at least two layers of the first material, wherein the mesh structure (18) is designed to at least partially overlap previously created layers of the at least one object (12) and to have at least one free area, so that the layers of the first material adjacent to the mesh structure (18) are at least partially connected to each other in the respective free areas, wherein portions of the mesh structure (18) which protrude beyond respective edge areas of the at least one manufactured object (12) after removal of unbound first material are removed manually or at least partially automatically, wherein a cutting tool is used for the removal.

Description

[0001] The invention relates to a method and a system for the additive manufacturing of objects.

[0002] Among additive manufacturing processes, 3D printing processes based on a powdered starting material, which is partially bonded with suitable binders, are of particular interest for industrial applications. To make this advantageous manufacturing process even more economical in the future, current research focuses on approaches suitable for mass production.

[0003] For mass production, the individual process steps must be accelerated without compromising the quality of the printed objects. At the same time, manufacturing steps should be combined where possible to enable a more efficient production cycle, allowing for the production of a larger quantity of finished objects in the same amount of time.

[0004] It is already known today to print multiple objects simultaneously within a production area. The production area is the space where the active processes of 3D printing or additive manufacturing take place, specifically the provision of powdered raw material and binding agents. In industrial processes, the use of metal powders and laser units in 3D printing systems is common in this context. Excess powdered raw material that has not been solidified with the binding agent or otherwise must be removed after the object has been created.

[0005] Automated depowdering remains a challenge. Ideally, this process should be completed quickly, while ensuring the finished objects are not damaged.

[0006] When draining excess powder, for example via suitable printing platforms with openings for this purpose, there is a risk that the finished printed object will move unintentionally within the production area. This is particularly true when multiple objects are being printed simultaneously, as draining or removing the powdery material can cause dangerous displacement of the objects and, consequently, damage to one another. Due to the complex structures of the objects being produced, a standardized depowdering process, which would be advantageous for accelerating the production cycle, is usually not practical. Current processes do not provide for the objects to be fixed in place, so they can sink onto each other during powder draining.As a result, particularly fragile areas or edges of the printed objects can be damaged. A common practice to date is therefore to manually remove the objects during depowdering, but this is very time-consuming and thus either impractical or too expensive for industrial mass production.

[0007] More recent approaches favor state-of-the-art solutions that incorporate, for example, molded-in support structures to locally fix manufactured objects. The resulting weakening of structures within the manufactured object is accepted as a consequence. Some of these state-of-the-art solutions are presented below as examples.

[0008] A manufacturing method and apparatus, as well as a data processing method, a data processing apparatus, and a corresponding data carrier, are disclosed as known from US 2017 326789 A1. The provided method is suitable for manufacturing an object. The method comprises depositing a first layer of building material onto a build platform. The method comprises depositing a binder onto the first layer of building material to bind at least a portion of the first layer together to form a support layer. The method comprises depositing a second layer of building material onto the support layer to form a spacer layer. The method comprises depositing a third layer of building material onto the spacer layer.The process involves the selective deposition of binder on the third layer to bond one or more areas of the third layer together to form a first layer of the object. Data processing methods, program carriers, data processing equipment, and manufacturing equipment for implementing the process are also provided.

[0009] Furthermore, US patent 2019 375009 A1 discloses a manufacturing method, a manufacturing apparatus, and a data method for creating a multilayer sintered object support structure. This involves using support substrates in certain additive manufacturing processes to facilitate the processing of an object. For additive manufacturing processes with materials that are sintered into a final part, a multilayer support substrate consisting of nested support and interface layers is created to support the object while reducing the influence of friction on part shrinkage during the sintering process.

[0010] Furthermore, additively manufactured articles with lattice supports are disclosed in publication WO 2020 091858 A1. Additionally, a method and a system for manufacturing such articles are disclosed. Articles with lattice supports capable of chemical removal are provided, along with methods and systems for their production. The method comprises forming a part from a powder in a powder bed deposition area of ​​an additive manufacturing device. An open-cell lattice, comprising an unbound region and a bound region, is formed in conjunction with at least one part of the component. The open-cell lattice is adapted to retain the part in the powder bed deposition area. The unbound region is adapted to form a cavity capable of receiving an etchant.

[0011] Other prior art documents include: EP 3 705 209 A1, US 2015 / 0 141 234 A1, US 2019 / 0 143 408 A1 and GB 2 479 616 A.

[0012] The invention is based on the objective of providing a method for the additive manufacturing of objects which ensures that manufactured objects are stabilized during and after depowdering in the manufacturing area.

[0013] In a preferred embodiment of the invention, a method for the additive manufacturing of objects is provided. This method comprises the following steps: First, a platform unit with an active manufacturing area is provided by a 3D printing system for the production of at least one object using an additive manufacturing process. At least one object is produced in the active manufacturing area using the 3D printing system, consisting of individual layers of a first powdered material and at least partially using a binder. At least one mesh structure made of a second material, different from the first, is embedded, with each mesh structure being placed between at least two layers of the first material.The mesh structure is designed to at least partially overlap previously created layers of the at least one object and to have at least one free area, so that the layers of the first material adjacent to the mesh structure are at least partially connected to each other in the respective free areas, wherein portions of the mesh structure that protrude beyond the respective edge areas of the at least one manufactured object after the removal of unbound first material are removed manually or at least partially automatically, using a cutting tool for the removal.

[0014] In this way, it is possible to provide a process for the additive manufacturing of objects that ensures that manufactured objects are stabilized in the production area during and after depowdering. The mesh structures are added to the production area from the outside as external components. In the simplest case, for example, only a mesh structure is inserted and printed in during the manufacturing process.

[0015] Multiple mesh structures can be incorporated, which are then inserted at regular intervals or after a defined number of layers. Each mesh structure serves to fix the manufactured objects, which can be components for various purposes, in a way that improves handling. This fixation allows, for example, the objects to be removed from the build area, also known as the powder bed, without damage. In other words, the mesh structures are inserted from the outside during a printing process to fix components, with adjacent layers—that is, layers of the printing process produced above and below the mesh structure—being bonded together through the open areas.

[0016] Therefore, the respective mesh structures are printed into the material during the manufacturing process, thus stabilizing at least one object being produced, especially after the actual manufacturing process is complete and further production steps are pending. This could involve, for example, the removal of excess initial material that was not bonded. Particularly when the excess initial material is automatically drained, such as through openings in the platform base, the printed mesh structures are surprisingly easy to use to stabilize or locally fix one or more objects during this process, reliably preventing unwanted sagging of the components or objects against each other. This prevents damage to finer component sections.Currently, in established processes, the finished components are removed from the powder bed after printing manually, using compressed air and a brush – a process reminiscent of archaeology. To make these processes more economical, various parties are currently working on solutions that would allow for automated powder removal.

[0017] The method presented here prevents damage to at least one manufactured object during the automated discharge of the powder. In particular, when several objects are manufactured simultaneously in the production area, the presented method prevents the finished objects from uncontrollably sinking or even falling over each other, as they are now, in effect, fixed in the powder bed or production area by the mesh structure (or multiple mesh structures).

[0018] The presented method thus easily prevents manufactured objects from getting scratched or from having corners or other features of the object structure break off. The mesh structure, as a separate component inserted from the outside, can be manufactured in any conceivable way. For example, it can itself be the product of an additive manufacturing process. The respective mesh structure can also be produced by any other manufacturing process. For example, the mesh structure can be woven or produced in any other way by linking threads or the like. Depending on the application, a customized shape and dimension of the mesh structure is conceivable, as long as the desired stabilizing effect is achieved.

[0019] A mesh structure is therefore inserted between at least two printed layers. In other words, for example, ten layers can be printed first, then a mesh structure inserted from the outside, and subsequently a defined number of layers of the object printed. Layers adjacent to the mesh structure can be connected to each other through the open areas.

[0020] A platform unit is essentially a flat work area, with an active manufacturing area being the area where active manufacturing steps are carried out. These include, for example, the application and processing of the initial material in any form, so that at least one object with its respective layers is produced. Various platform unit variants are already in use, such as those with connectable, at least partially retractable units and corresponding boundary elements at the edges of the manufacturing area. Platform units are also known that are designed to drain excess initial material through corresponding openings after the at least one object has been completed.

[0021] In a further preferred embodiment of the invention, a system for the additive manufacturing of objects is provided. Such a system comprises a 3D printing system for the production of at least one object and an insertion device for the at least partially automatic insertion of mesh structures during the manufacturing process of the at least one object. The presented system is designed for carrying out the method according to claims 1 to 9. The aforementioned advantages also apply, insofar as they are transferable, to the presented system.

[0022] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0023] In a further preferred embodiment of the invention, it is provided that the insertion of the at least one network structure is carried out manually or at least partially automatically.

[0024] Manual insertion offers the advantage that the mesh structure can be individually inserted, thus enabling individual quality control. Any necessary improvements can also be made directly by a person. Manual insertion is particularly advantageous if the mesh structure is somewhat fragile before insertion. Manually, it is then possible to, for example, unroll or otherwise manipulate the mesh structure. Once the mesh structure (or multiple structures) is inserted, the stabilizing effect takes effect. A partially automated insertion process offers the advantage of further accelerating the process and thus enabling efficient industrial production.Automated manufacturing is particularly advantageous when the network structure has a certain basic stability to offer sufficient stability even to a single object.

[0025] In a further preferred embodiment of the invention, the first material comprises a metal powder, wherein the metal powder is selected from: metal powder comprising stainless steel, preferably stainless steel 316L and / or stainless steel 17-4PH, metal powder comprising tool steel, preferably tool steel DP600, metal powder comprising copper alloys, metal powder comprising aluminum alloys, preferably AlSi10Mg, or wherein the first material comprises sand or a technical ceramic, preferably a technical ceramic comprising Al2O3, preferably a technical ceramic comprising ZrO2.

[0026] Therefore, the presented process, in this variant, is designed for the production of corresponding metal components. For example, it is conceivable that the presented process could be used in combination with or as a supplement to a binder jetting process. Binder jetting processes are characterized by the fact that metallic starting powder (first material) is bonded layer by layer into the component shape using a binder. The resulting component is also referred to as a green part and is characterized by limited strength, as it is held together only by the applied binder. Before the components can be removed from the powder bed, the binder usually has to be thermally activated and cured. This is known, for example, as a curing process. Final strength is achieved through a subsequent sintering process at the end of the entire manufacturing process.

[0027] Furthermore, in a further preferred embodiment of the invention, the second material is made of a plastic, wherein the plastic is selected from: plastic comprising plastic PA12, plastic comprising plastic PA12 GF / GB, plastic comprising plastic TPU 90A.

[0028] The use of plastic offers the advantage that the mesh structure (or multiple mesh structures) can provide sufficient stability while also being easy to handle. A plastic mesh structure is sufficiently lightweight, so the insertion process is not particularly difficult and can therefore be partially automated with manageable effort. Furthermore, the plastic material facilitates at least partial removal later on. For example, a plastic mesh structure can be easily partially cut or torn when the stabilizing effect is no longer needed and the object(s) are to be removed from the production area.

[0029] Furthermore, in a further preferred embodiment of the invention, the network structure comprises a network of threads which define respective free areas, wherein the threads preferably have a thickness of 0.001 mm to 2 mm, preferably a thickness of 0.001 mm to 1 mm, preferably a thickness of 0.001 mm to 0.5 mm, preferably a thickness of 0.001 mm to 0.1 mm, wherein the free areas have an area of ​​0.5 mm². 2 up to 400 mm 2 , preferably an area of ​​3 mm 2 up to 200 mm 2 , preferably an area of ​​15 mm 2 up to 100 mm 2 and / or wherein the active manufacturing area of ​​the platform unit has a size of 1,600 x 1,200 mm, preferably 1,000 x 500 mm, preferably 430 x 320 mm and / or wherein the active manufacturing area of ​​the platform unit is user-defined and scalable in terms of its size.

[0030] Depending on the application, in terms of the objects to be manufactured and their associated complexities, a suitable mesh structure can be provided. It is also conceivable to use a mesh structure made from threads of varying properties and thicknesses. For example, if particularly fine threads are used, a correspondingly larger number of individual mesh structures need to be printed. Finer threads thus form the basis for a particularly fragile mesh structure, which, while offering only limited stability, is also easier to remove later. This trade-off is therefore crucial for the selection in each specific application.It is conceivable that this could be determined in advance using a computer-aided process or based on a computer simulation, so that a precisely fitting mesh structure (or several) and an appropriate number of mesh structures with the correct spacing are provided. Such a simulation process can, for example, incorporate the specific geometry of the object to be manufactured or, if multiple objects are being printed, determine the number and location of the mesh structures. In this way, the appropriate free spaces can also be determined. These free spaces, which can have any type of mesh within the structure, can be individually designed and, in particular, placed where the object to be printed requires special strength.In this way, it is possible to provide a stabilizing effect from the mesh structure without excessively or even at all impairing the structural integrity of the objects being manufactured. Depending on the number of objects or the shape and design of each individual object, a suitable dimension for the active manufacturing area of ​​the platform unit can be selected. Furthermore, the specific properties and number of mesh structures can be provided according to the size of the platform unit's active manufacturing area.

[0031] In a further preferred embodiment of the invention, it is provided that the layers of the first material have a thickness of 10 µm to 200 µm, preferably a thickness of 20 µm to 150 µm, preferably a thickness of 30 µm to 120 µm, preferably a thickness of 35 µm to 100 µm.

[0032] Depending on the intended purpose of the manufactured objects, the process produces different thicknesses. It is also conceivable that the thicknesses used vary within the object being manufactured and / or that areas near or even in direct contact with the mesh structures have a distinct thickness, thus providing a particularly effective stabilizing effect for the printed mesh structures. For example, adjacent layers are designed according to the thickness of the printed mesh structure.

[0033] In other words, it is conceivable that this process is calculated in advance using suitable simulation methods, so that the desired effects can be produced in the intended manner and to a suitable extent using the presented method.

[0034] Portions of the network structure that protrude beyond the respective edge areas of the at least one manufactured object after the removal of unbound first material are removed manually or at least partially automatically.

[0035] In this way, it is possible to quickly remove the mesh structure (or several of them), for example, manually. For this purpose, the mesh structure is designed so that manual removal is possible without excessive force. For instance, several mesh structures can initially be used for stabilization, and these structures are designed so that they can subsequently be removed by tearing them apart by hand around the object. The mesh structures can also have designated areas to support this process or even provide a visual guide for the user. At least a partially automated process is advantageous because it allows for a more efficient procedure.

[0036] A cutting tool is used for removal. Depending on the mesh structure used, a suitable cutting tool can be selected. A cutting tool not only simplifies and speeds up the removal process but also ensures clean edges. This prevents torn ends from complicating the process.

[0037] Finally, in a further preferred embodiment of the invention, a thermal method is used to remove protruding respective parts of the network structure and / or existing parts of the network structure in the at least one manufactured object, and / or a chemical method is used to at least partially dissolve the network structure.

[0038] Such a thermal process can either be implemented separately or combined with a subsequent sintering process. It is also conceivable that a subsequent sintering process alone constitutes this thermal process, so that any remaining residues or components are completely removed during this process, which is occurring anyway. This process is thus a combustion of the remaining components of the network structures. It is also conceivable that a chemical process designed for this purpose is used. It is also conceivable that a chemical process is used first, and any remaining residues are then removed during the thermal process.A chemical process also offers the advantage of efficient and rapid removal and can, for example, be carried out using a submersion method, whereby at least partial automation is feasible in this context.

[0039] The presented method and system can be used, for example, for component solutions manufactured using binder jetting or similar processes. In principle, the presented method and system can be used wherever binder jetting parts are manufactured.

[0040] Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

[0041] The invention is explained below using exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1 a schematic sectional view of a manufacturing area of ​​an additive manufacturing process according to the state of the art before and after depowdering; Fig. 2 a schematic sectional view of a manufacturing area of ​​an additive manufacturing process according to the present invention before and after depowdering; Fig. 3. A process flow diagram of a process for the additive manufacturing of objects; Fig. 4 A schematic representation of a system for the additive manufacturing of objects.

[0042] Fig. Figure 1 shows a schematic sectional view of a manufacturing area 10 of a state-of-the-art additive manufacturing process before and after depowdering. On the left side of the image plane, a total of six manufactured objects 12 are shown in a powder bed 14. The manufacturing area 10 is located on a platform unit 16, and this platform unit 16, together with this active manufacturing area 10, is part of a 3D printing system (not shown in detail) for the production of at least one object 12 using an additive manufacturing process. The powder bed 14 consists primarily of a first material, which is partially bonded to form the objects 12 by means of a binder in the 3D printing system.

[0043] The additive manufacturing process is exemplified by the binder jetting process, which is suitable for the production of metal parts. In this process, the powder present in the powder bed 14 can be a metallic starting powder. The metallic starting powders are bonded layer by layer into the component or object shape using the binder. The resulting objects are also referred to as green parts and are characterized by limited strength, as they are held together only by the applied amounts of binder. Before the components can be removed from the powder bed 14, the binder (or binder in general) must be thermally activated and cured. This process step is also known as the curing process. The final strength is achieved through a sintering process at the end.

[0044] The figure on the right shows the current situation after the excess first material has been drained from the powder bed 14. The objects 12 have sunk onto each other as the powder material was drained. The lightning bolt symbols illustrate the potential risk of damage during this uncoordinated process.

[0045] Fig. Figure 2 shows a schematic sectional view of a production area 10 of an additive manufacturing process according to the present invention before and after depowdering. The situation shown is of the production area 10 and the objects 12 located therein. Fig. 1. However, in this case, eight network structures 18 are printed into the objects 12 during the manufacturing process. These eight network structures 18 are essentially parallel to each other and to a platform unit 16. It is conceivable, however, that fewer or more network structures 18 are provided. In the extreme case, it is conceivable that only one network structure 18, designed for this extreme case, is provided. Instead of essentially parallel insertion of the network structures 18, it is also conceivable that at least one network structure 18 is not inserted essentially parallel in order to provide additional stability between separate objects 12.In any case, the network structures 18 stabilize the various objects 12, which can also be referred to as components, in such a way that they do not fall into each other after the release of excess material (see situation on the right side in relation to the image plane) and thus damage or other negative effects are reliably prevented.

[0046] In other words, the mesh structures 18, which can also be referred to simply as meshes, are likewise located within component areas and are printed into the components. When the powder (first material) is discharged, the meshes ensure that the components remain at their predefined points in the build chamber or manufacturing area 10, as they are effectively held in place by the meshes. Thus, the presented method and system provide for the insertion of fine meshes, which, as shown, span the entire build chamber, at intervals of a defined number of layers during the printing process and are then printed in place during the manufacturing process.Following the complete removal of the powder, the meshes or mesh structures 18 are then cut off close to the printed components or objects 12, for example, using cutting tools, and the components are thus removed. It is also conceivable, for example, that the mesh structures 18 (or their remaining remnants) on the objects 12 are subsequently burned or otherwise removed, for example, in a sintering process or the like. In this respect, for example, dissolving or removing the mesh structures 18 by residue-free combustion in a subsequent sintering process is conceivable.

[0047] It is conceivable that the network structures 18 are made of unspecified threads or the like, which surround or frame respective free areas, also unspecified. The threads could, for example, be composed of several individual threads joined together or produced from individual components. It is also conceivable that the network structures 18, each made of a second material different from the first, could be manufactured beforehand using a separate 3D printing process. It is also conceivable that these network structures 18 could be punched out of a sheet or the like. It is also conceivable that the network structures 18 could be manufactured using an injection molding process. The threads could be arranged regularly or at least regularly in certain areas.It is also conceivable that an individual arrangement of the threads, tailored to the application, is planned. In this context, it is conceivable that the respective free areas are arranged regularly, or at least regularly in certain areas, with regard to shape and position. It is also conceivable that the free areas, for example, have essentially rectangular shapes or any other polygonal shapes. It is also conceivable that the free areas have essentially circular shapes. Any mixture of the various shapes presented is also conceivable. It is also conceivable that, depending on the number of objects 12 to be manufactured and their properties, shape, and relative position of the network structures 18 in the powder bed, they are calculated and produced in advance.

[0048] In other words, it is conceivable, for example, that the shape and position of the individual threads or comparable components of the network structures 18 and the resulting free areas are created individually, so that an optimal support effect results.

[0049] Fig. Figure 3 shows a process flow diagram 100 of a process for the additive manufacturing of objects 12. In a first step 110, a platform unit 16 with an active manufacturing area 10 is provided by a 3D printing system 22 for the production of at least one object 12 using an additive manufacturing process. In a second step 120, at least one object 12 is produced from individual layers of a first powdered material in the active manufacturing area 10 using at least a binder by means of the 3D printing system 22. In a third process step 130, at least one mesh structure 18 made of a second material, different from the first material, is inserted, which is arranged between at least two layers of the first material. The mesh structure 18 is designed to cover already created layers of the at least one object 12, at least partially overlapping them.

[0050] Furthermore, the network structure 18 is designed to have at least one free area, so that the layers of the first material adjacent to the network structure 18 are at least partially connected to each other in the respective free areas.

[0051] Fig. Figure 4 shows a schematic representation of a system 20 for the additive manufacturing of objects 12. The system 20 is shown with a 3D printing system 22 for the production of at least one object 12 and an insertion device 24 for the at least partially automatic insertion of mesh structures 18 during the manufacturing process of the at least one object 12. The depicted system 20 is designed for carrying out the method according to claims 1 to 9. Reference symbol list 10 Production area 12 objects 14 Powder bed 16 platform units 18 Network structure 20 System 22 3D printing systems 24 Insert device 100 Process Flow Diagram 110 first procedural step 120 second procedural step 130 third procedural step

Claims

[1] Methods for the additive manufacturing of objects (12) comprising the following steps: • Providing a platform unit (16) with an active manufacturing area (10) of a 3D printing system for the production of at least one object (12) using an additive manufacturing process; • Manufacturing the at least one object (12) from individual layers of a first powdered material in the active manufacturing area (10) using at least a binder, by means of the 3D printing system, characterized by that the procedure includes the following further steps: • Inserting at least one mesh structure (18) made of a second material different from the first material, which is arranged between at least two layers of the first material, wherein the mesh structure (18) is designed to at least partially overlap previously created layers of the at least one object (12) and to have at least one free area, so that the layers of the first material adjacent to the mesh structure (18) are at least partially connected to each other in the respective free areas, wherein portions of the mesh structure (18) which protrude beyond respective edge areas of the at least one manufactured object (12) after removal of unbound first material are removed manually or at least partially automatically, wherein a cutting tool is used for the removal. [2] Method according to claim 1, wherein the insertion of the at least one network structure (18) is carried out manually or at least partially automatically. [3] A method according to any of the preceding claims, wherein the first material comprises a metal powder, wherein the metal powder is selected from: metal powder comprising stainless steel, preferably stainless steel 316L and / or stainless steel 17-4PH, metal powder comprising tool steel, preferably tool steel DP600, metal powder comprising copper alloys, metal powder comprising aluminum alloys, preferably AlSi10Mg or wherein the first material comprises sand or an engineering ceramic, preferably an engineering ceramic comprising Al2O3, preferably an engineering ceramic comprising ZrO2. [4] Method according to any of the preceding claims, wherein the second material is made of a plastic, wherein the plastic is selected from: plastic comprising plastic PA12, plastic comprising plastic PA12 GF / GB, plastic comprising plastic TPU 90A. [5] Method according to one of the preceding claims, wherein the network structure (18) comprises a network of threads which define respective free areas, wherein the threads preferably have a thickness of 0.001 mm to 2 mm, preferably a thickness of 0.001 mm to 1 mm, preferably a thickness of 0.001 mm to 0.5 mm, preferably a thickness of 0.001 mm to 0.1 mm, wherein the free areas have an area of ​​0.5 mm² 2 up to 400 mm 2 , preferably an area of ​​3 mm 2 up to 200 mm 2 , preferably an area of ​​15 mm 2 up to 100 mm 2have and / or wherein the active manufacturing area (10) of the platform unit (16) has a size of 1,600 x 1,200 mm, preferably 1,000 x 500 mm, preferably 430 x 320 mm and / or wherein the active manufacturing area (10) of the platform unit (16) is user-defined and scalable in size. [6] Method according to claim 5, wherein the layers of the first material have a thickness of 10 µm to 200 µm, preferably a thickness of 20 µm to 150 µm, preferably a thickness of 30 µm to 120 µm, preferably a thickness of 35 µm to 100 µm. [7] Method according to one of the preceding claims, wherein a thermal method is used to remove protruding respective parts of the network structure (18) and / or existing parts of the network structure (18) in the at least one manufactured object (12) and / or wherein a chemical method is used to at least partially dissolve the network structure (18). [8] System (20) for the additive manufacturing of objects (12) comprising a 3D printing system (22) for the production of at least one object (12) and an insertion device (24) for the at least partially automatic insertion of mesh structures (18) during the manufacturing process of the at least one object (12), wherein the system (20) is designed for carrying out the method according to claims 1 to 7.

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