Additive manufacturing of component in food industry

Abstract

To provide a method, a system, and an assembly for additively manufacturing a component for use with food, in which the component has improved hygienic properties and quality of a surface of the component that come into contact with a product located therein.SOLUTION: In the manufacturing section 130 of the additive manufacturing device 110, the method comprises: producing a processing layer 114 from a powder material 112, which is preferably a metallic powder; and exposing the processing layer by means of the beam melting system 140. The beam melting system applies hatch process parameters to form at least one hatch region of the additive manufactured part 116; and scans and exposes the processing layer in such a way that at least one contour region is formed using contour process parameters, wherein a plurality of adjacent contour lines are generated in the contour region and / or the contour region is at least partially exposed multiple times.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to methods, systems and assemblies for manufacturing parts, particularly parts for use with food products, that involve additive manufacturing processes. [Background technology]

[0002] For the filling of fluids in the food sector, filling valves of different types and manufacturing methods are known. When complex geometries inside filling valves, especially when complex channel structures have to be realized ("bionic", "organic" designs), additive manufacturing concepts, also known as "3D printing" or "generative manufacturing", come into question.

[0003] From US Pat. No. 5,399,633 an additively manufactured composite filling valve for filling still and carbonated products is known.

[0004] Additive manufacturing has the advantage that complex geometries can be created, the flow and exit behavior of fluids can be optimized, dead volumes can be eliminated, sealing points can be avoided and therefore the filling valves can be better cleaned, resulting in a particularly clean design and a filling that protects the product.

[0005] The parts can be manufactured by different additive methods, such as, for example, SLM ("Selective Laser Melting"), EBM ("Electron Beam Melting"), LENS ("Laser Engineering Net Shape"), MPA ("Metal Powder Application"), WAAM ("Wire Arc Additive Manufacturing"), FDM ("Fused Deposition Modeling"), BJ ("Binder Jetting") or NPJ ("Nano Particle Jetting").

[0006] The challenge in additive manufacturing is to ensure a sufficiently high surface quality, which is essential especially in the food sector. For the hygienic filling of beverages, a surface roughness of Ra ≦ 0.8 μm is aimed for product-contact parts. In this case, Ra stands for the average roughness value as a standardized measure of surface roughness. Furthermore, additive manufacturing can result in defects in the material (pores, shrinkage cavities, cracks, etc.), for example due to gas inclusions, poor bonding or delamination. Therefore, post-processing of additively manufactured parts is often necessary, especially of the surfaces that will come into contact with the product.

[0007] Furthermore, hybrid methods are known that combine layer-by-layer additive build-up with sequential downstream cutting post-processing. However, such methods usually cannot be dispensed with, since especially for complex geometries (e.g. swirling flow geometries, channels with strongly varying radii of curvature, etc.), tool changes between the additive build-up and the cutting post-processing can lead to tool change step angles in the form of material staircase steps.

[0008] Well-accessible component faces and component corners can be improved by conventional methods such as classical electrolytic polishing, sliding grinding, post-machining (turning, drilling, milling, etc.). However, components with channels and other internally located contours that are partially undercut and difficult to access from the outside, but which come into direct or indirect contact with the food, cannot be post-machined by these methods. However, technologies have been developed that address this issue, such as abrasive flow machining, Hirtisieren, MMP ("Micro Machining Process"), DLyte, and HIP ("Hot Isostatic Pressing").

[0009] In abrasive flow machining, a paste ("liquid file") is pumped under vibration into the channels to be machined. Hirtisieren is based on the application of liquid machining media and kinematically controlled electrochemistry. MMP refers to a special mechanical, physical and chemical method in which the part is immersed in a bath containing liquid and microtools, which are excited with high energy, thereby removing roughness. DLyte is a dry surface process for grinding and polishing metals by ion transport with free solids, where an electric current is combined with the part movement with an electropolishing medium. In HIP, the part is compressed under high pressure and temperature, which leads to an increase in relative density and a decrease in porosity.

[0010] The surface quality that can be achieved by such post-processing methods depends heavily on the initial roughness, i.e. the roughness present immediately after additive manufacturing, and on the texture quality in the near-surface region, which can be called the "as-built surface", meaning the surface immediately after additive manufacturing.

[0011] Regardless of how the additive build-up is carried out (e.g. powder, wire, filament, etc.), defects can occur in the structure. For example, when powder particles melt, the energy input of the energy source (e.g. laser beam or electron beam) and foreign bodies in the interaction area can cause stains, porosity, shrinkage cavities, bond defects, etc. Numerous porosity occurrences can be seen especially in the edge area, i.e. in the transition between the contour and the inside of the body or part defined by the contour, the so-called "hatch". For hatching and contour, different process parameters are usually used, i.e. fast hatching and slow contour scanning are performed, in order to achieve a good compromise between economy and quality.

[0012] Post-processing of material removal can expose porosity that occurs in the case of melting, which can lead to unexpected deterioration of the surface quality again during the surface treatment following additive manufacturing. In this case, the above-mentioned post-processing methods have specific disadvantages. With Hirtisieren and MMP, it is difficult to achieve the desired surface quality of Ra ≦ 0.8 μm, at least for certain geometries (e.g. small diameter channels). With abrasive flow processing, due to material removal, the above-mentioned defects in the material (porosity) can be exposed, especially in the regions close to the edges. Furthermore, channels with a non-constant cross section and curvature over the channel contour can have non-uniform material removal, which results in non-uniform surface quality. The applicability of the DLyte method is also limited by the channel size and channel geometry. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] DE 102020129102 Summary of the Invention [Problem to be solved by the invention]

[0014] The object of the present invention is to improve the additive manufacturing of parts, preferably parts for use with food, in particular the hygiene properties and the quality of the surfaces of the parts that come into contact with the (liquid) product located therein. [Means for solving the problem]

[0015] The above problem is solved by a method having the features of claim 1, by a method having the features of claim 5, by a system having the features of claim 10 and by an assembly having the features of claim 14. Advantageous developments can be seen from the dependent claims, the following description of the invention and the description of preferred embodiments.

[0016] The method according to the invention is used for additively manufacturing parts, in particular parts for use with food products. In general, additively manufactured parts that are used in direct or indirect contact with food products, in particular in filling and / or packaging equipment, can be produced in this way. This includes components of fillers, in particular in beverage filling equipment, preferably housing parts with product lines or channels of complex geometry. However, the manufacturing concept described herein is not limited thereto.

[0017] The method is performed by an additive manufacturing apparatus having a build section and a beam melting system.

[0018] First, in the build section of the additive manufacturing machine, a working layer is built from a metal powder, which may be made of various metals, in particular stainless steel, preferably stainless steel 316L, but also other metals and alloys, such as titanium or aluminum.

[0019] The processing layer is then exposed by a beam melting system, thereby locally melting the powder material of the processing layer, where the beam melting system scans and exposes the processing layer such that hatch process parameters are applied to form at least one hatch region of the additively manufactured part, and contour process parameters are applied to form at least one contour region.

[0020] A contour region is understood to be a region of an additively manufactured part that is formed in the surface region of the part. The surface is usually a part of the contour region, but this part extends further into the volume of the part. In other words, a contour region is understood to be a region near the surface of the part, or an edge region. For simplicity, in this document it is always referred to only as a contour region or a contour, but this always means such a near-surface region.

[0021] A hatched area is understood to be an area of ​​an additively manufactured part where a quantity of material should be quickly deposited to achieve rapid production. This is usually an area within the volume of the part. The hatched area can be surrounded by a contour area, which then forms the actual part surface.

[0022] Thus, the beam melting process is configured with various process parameters, including, for example, the laser or electron beam power of the beam melting system, the scan speed, the track spacing, and / or the layer thickness of the fabrication layer built by the build section. In this specification, the process parameters applied for the hatched regions are referred to as "hatch process parameters" and the process parameters applied for the contoured regions are referred to as "contour process parameters." A controller can provide the process parameters and can correspondingly open-loop and / or closed-loop control the additive manufacturing device.

[0023] The hatched and contoured regions are preferably formed with different process parameters, i.e. the hatched and contoured process parameters are preferably at least partially different, for a good compromise between economy and quality. In particular, the hatched regions can be scanned or exposed at a higher scanning speed than the contoured regions. However, alternative or additional process parameters, e.g. laser or electron beam power and / or track spacing, can be modified in order to differentiate the contoured and hatched regions process-technically.

[0024] According to the invention, a plurality of adjacent contour lines is generated in at least one contour region. Alternatively or additionally, the contour region is at least partially exposed several times.

[0025] In this case, the generation of multiple contours and / or multiple exposures refers to the exposure process of the current work layer. Typically, the modeling and exposure steps of the work layer are performed multiple times in a continuous process, whereby the additively manufactured part is built up layer by layer.

[0026] By generating multiple contour lines in the contour area and / or exposing the contour area several times, the discontinuous transition area between the hatched area and the contour area is transferred to the interior of the part, whereby an improvement in surface quality can be achieved. This improvement can then include a direct reduction in the porosity (number and size of pores) in the part. The contour area can also be formed with a greater thickness by generating multiple adjacent contour lines. In other words, a thicker surface area is thus formed.

[0027] By abrasive post-processing, which may possibly be carried out downstream, the surface quality is improved and / or the thickness of the contour area is increased so that pores are not exposed, and thus an overall reduction in surface roughness can be achieved. The improved as-built surface quality, if it does not yet meet the hygiene requirements, shows an improved initial roughness for post-processing. In the possible post-processing of the part, the contour area is partially completely removed, reducing the risk of exposing the hatch area, which is usually of lower quality than the product-contact surface. Furthermore, by the possible multiple exposures, bonding defects in the middle area are eliminated. Overall, therefore, a reduction in the number and size of pores in the area near the edge, i.e. on the product-contact surface of the part, can be achieved.

[0028] In this way, hygienic internal surfaces with a roughness of Ra≦0.8 μm or even high-gloss surfaces with Ra<0.2 μm, especially when applying the MMP method, can be achieved, which reduces the risk of microbial contamination of the components and allows them to be cleaned easily and reliably.

[0029] If several adjacent contour lines are generated in at least one contour region, a new exposure of the intermediate spaces of the contour lines is preferably performed, in particular with modified process parameters for the contour lines, in such a way that the quality of the contour region can be further improved.

[0030] In a development, the contour lines can be arranged in such a way that an overlap occurs between them. In a development, an overlap between the contour lines and the hatched areas can also be achieved.

[0031] The contour process parameters are preferably optimized such that the porosity in the contour region, i.e. the surface region, is minimized.

[0032] Preferably, at least one hatched area is exposed using contour process parameters, which eliminates the potentially numerous porosity in the transition area between the hatched area and the contour area, thereby producing a substantially porosity-free near-surface structure.

[0033] An additional measure to improve the surface quality of the product-contact surface of the component is the use of a particularly thin working layer in combination with a fine powder material. Preferably, for this purpose, a powder material having a particle size of up to 20 μm, in particular less than 15 μm, is applied in combination with a layer thickness of the working layer of up to 20 μm, in particular less than 15 μm. Particularly preferably, the layer thickness of the working layer is greater than the particle size of the powder material.

[0034] This measure can also be used independently.The above problem is therefore further solved by a method for additively manufacturing a part, in particular a part for use with food products, by means of an additive manufacturing apparatus having a build section and a beam melting system, the method comprising: building a work layer from a powder material in the build section of the additive manufacturing apparatus, and exposing the work layer by means of the beam melting system, whereby the powder material of the work layer is locally melted, whereby as powder material a fine powder having a particle size of up to 20 μm, preferably less than 15 μm, is applied in combination with a layer thickness of the work layer of up to 20 μm, preferably less than 15 μm, the layer thickness of the work layer being preferably greater than the particle size of the powder material.

[0035] Preferably, the exposure of the processing layer is followed by subtractive machining of the contour area by a subtractive processing device, which includes, for example, a milling machine. In this case, the additive manufacturing method is based on a hybrid method in which a layer-by-layer additive build-up is combined with a subtractive post-processing that may be performed sequentially downstream. In other words, a tool change is made to a subtractive processing device, preferably a milling head, according to the number of additive build layers individually defined in the additive manufacturing device. The milling head then mechanically post-machines the geometry generated up to that point. This process is repeated until the part is completely built up. The application of such a hybrid method can further improve the surface quality of the part.

[0036] In such hybrid methods, subtractive processing during additive manufacturing can result in corners or other surface defects in the part. These can be minimized by optimizing the cutting edge geometry of the subtractive processing device, for example by using cutting edges with rounded edges instead of sharp cutting edges. Alternatively or additionally, simulation-assisted distortion compensation can be performed to prevent distortions caused, for example, by thermally induced internal stresses during the additive building process and by the release of internal stresses in post-subtractive processing.

[0037] The above problem is further solved by a method for manufacturing a part, in particular a part for use with food, which method comprises additively manufacturing the part by means of an additive manufacturing apparatus, whereby the additive manufacturing is preferably carried out according to one of the above-mentioned embodiment variants, and post-processing the surface of the part by one or more post-processing methods, preferably comprising abrasive flow machining and / or Hirtisieren and / or MMP and / or DLyte and / or HIP.

[0038] The additive manufacturing of the parts can be carried out with the above-mentioned hybrid methods, which can be combined with post-processing to remove or homogenize powder residues, weld spatters and tool change step angles, preferably hybrid DED or hybrid SLM methods combined with post-processing methods, such as abrasive flow machining or Hirtisieren.

[0039] Preferably, in order to post-process the additively manufactured part according to the above description, at least two post-processing methods are combined, which perform two downstream processing steps of the part. For example, the post-processing can include a roughing process, in which a rough material removal is performed, and a finishing process, which generates the final surface after the roughing process. Particularly preferably, an abrasive flow process and an MMP process or a Hirtisieren or DLyte process are combined as post-processing methods. The order of application of the post-processing methods can be selected depending on the respective application and / or the additive material and / or the part geometry. For example, an abrasive flow process can be used for the roughing process and an MMP process or a Hirtisieren or DLyte process for the finishing process. However, this order can also be reversed depending on the requirements. In this way, the surface quality of the part can be further improved.

[0040] The above problem is further solved by a system for additively manufacturing parts, in particular parts for use with food, comprising an additive manufacturing device including a building section for building a processing layer from a powder material, preferably a metal powder, and a beam melting system capable of exposing the processing layer and thereby locally melting the powder material of the processing layer, and a control device communicating with the additive manufacturing device and configured to cause the beam melting system to scan and expose the processing layer such that at least one hatch area of ​​the additively manufactured part is formed by applying hatch process parameters and at least one contour area is formed by applying contour process parameters, the control device being further configured to cause the beam melting system to generate a plurality of adjacent contour lines in the at least one contour area and / or to expose at least one contour area at least partially several times.

[0041] The features, technical effects, advantages and embodiments described with respect to the method apply to the system as well.

[0042] The manufacturing method and its parameterization are therefore executed by a control device comprising suitable open-loop and / or closed-loop controllers, which communicate with the additive manufacturing device and with any possible post-processing system, in particular with the various devices and assemblies of the additive manufacturing device and the post-processing system, etc. The control device is signal-technically connected with the components which are open-loop or closed-loop controlled and / or read.

[0043] The communication between the control device and the components to be open-loop or closed-loop controlled and / or read can be wired or wireless, digital or analog. Correspondingly, the control device can receive and / or transmit signals (control signals, data, etc.), in which connection both unidirectional and bidirectional signal transmissions are included in the term "communication". In this case, the control device does not necessarily have to be realized by a central computing device or electronic controller, but includes distributed and / or multi-stage systems, control networks, cloud systems, etc. Furthermore, the control device can be an integral part of or communicate with a higher-level equipment control device. The control device can also communicate with a lower-level equipment control device, i.e. a control device assigned to the corresponding equipment.

[0044] Preferably, for the reasons mentioned above, the control device is configured to cause the beam melting system to generate a plurality of adjacent contour lines in at least one contour region, as well as to newly expose intermediate spaces between the contour lines using process parameters that have been changed in particular for the contour lines.

[0045] Preferably, for the reasons discussed above, the control device is configured to cause the beam melting system to apply contour process parameters to expose at least one hatch area and correspondingly achieve an expansion of the contour area and / or an improvement in the surface quality of the contour area.

[0046] Preferably, the control device is configured to cooperate with the layer creator to generate a particularly thin working layer in the building section of the additive manufacturing device in combination with a finer powder material. Preferably, for this purpose, a powder material having a particle size of up to 20 μm, in particular less than 15 μm, is applied in combination with a layer thickness of the working layer of up to 20 μm, in particular less than 15 μm. Particularly preferably, the layer thickness of the working layer is greater than the particle size of the powder material.

[0047] Preferably, for the reasons mentioned above, the additive manufacturing device comprises a subtractive machining device, for example including a milling machine, and the control device is configured to perform subtractive machining of the contour area by the subtractive machining device following exposure of the machining layer.

[0048] The above problem is further solved by an assembly for manufacturing a part, in particular a part for use with food, which comprises a system for additively manufacturing the part, preferably according to one of the above mentioned embodiment variants, and a post-processing system for post-processing the surface of the part by one or more post-processing methods, preferably comprising abrasive flow machining and / or Hirtisieren and / or MMP and / or DLyte and / or HIP.

[0049] The features, technical effects, advantages and embodiments described with respect to the methods and systems apply to the assemblies as well.

[0050] Preferably, the post-processing system is set up to combine at least two post-processing methods for the reasons mentioned above, whereby the post-processing comprises a roughing process for rough material removal and a finishing process for producing the final surface, the post-processing system being preferably set up to combine an abrasive flow process with an MMP process or a Hirtsisieren or DLyte process, in a sequence adapted to the result to be achieved.

[0051] Other advantages and features of the present invention will become apparent from the following description of the preferred embodiments. The features described therein can be implemented alone or, unless the features are inconsistent, in combination with one or more of the above features. In that case, the following description of the preferred embodiments will be made with reference to the accompanying drawings.

[0052] Other preferred embodiments of the present invention will be explained in more detail in the following description of the figures. [Brief description of the drawings]

[0053] [Figure 1]1 illustrates a side cross-sectional view of an exemplary impregnator that is at least partially sculptable by additive manufacturing methods. [Diagram 2] FIG. 1 is a schematic diagram of a system for additive manufacturing of parts suitable for use in the food industry. [Figure 3A] FIG. 2 is a schematic cross-sectional view of a part with hatched areas and simplified outlines. [Figure 3B] 1 is a schematic cross-sectional view of a part having a hatched area and a contour area including a plurality of contour lines. [Figure 3C] FIG. 2 is a schematic cross-sectional view of a part having a hatched area and a contour area that is exposed multiple times and includes multiple contour lines. [Figure 4] FIG. 3D view of the additively manufactured valve portion of the filler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] Hereinafter, preferred embodiments will be described with reference to the drawings. In this description, the same reference numerals will be used to designate elements in each drawing that are the same, similar, or have the same functions, and descriptions of these elements will be partially omitted to avoid redundancy.

[0055] 1 shows a vertical cross-sectional view of a filler 10. The filler 10 is used to fill containers (not shown) with a product, preferably a beverage, in a beverage filling facility. The product to be filled could be, for example, water (still or carbonated), soft drinks, smoothies, dairy products, beer, wine, mixed drinks, etc.

[0056] The impregnator 10 has an elongated cylindrical housing 20, the main extension of which defines a longitudinal direction, which in the assembled state normally coincides with the direction of gravity.

[0057] The housing 20 can divide the filler 10 into three parts, namely the upper valve part 30, the flange part 40 and the lower valve part 50, but this is by way of example only. This three-part division of the filler 10 serves for a substantially economical production. The upper valve part 30 can be additively or generatively built directly and seamlessly on the flange part 40, for example by selective laser melting (SLM) or another 3D printing method. The flange part 40 can be produced in a conventional manner, for example by turning, milling, laser cutting, and can therefore be built particularly economically. The lower part 50 of the filler 10 is placed or printed, preferably also additively, from the other side of the flange part 40, so that the flange part 40 can serve as a base or anchor for the constructions on both sides, namely the upper valve part 30 and the lower valve part 50.

[0058] The upper valve portion 30 illustratively accommodates several connections, including a first product connection 31 and a second product connection 32. The two product connections 31, 32 are configured to connect to corresponding product supply lines to direct the fill product to different channels within the filler 10, as will be explained in more detail below.

[0059] Additionally, upper valve portion 30 illustratively includes a gas connection 33 adjacent to which is gas channel 36a, which may be used, for example, to supply pre-pressurized gas to the container and / or to conduct return gas from the container that is exhausted during filling.

[0060] The filler 10 includes a first product line 34, which in this embodiment is a product space surrounded by the housing 20, fluidly connected to the first product connection 31. Additionally, there is a second product line 35, which in this embodiment is a product space surrounded by the housing 20, fluidly connected to the second product connection 32 and which splits into a number of jacket channels 35a (see also FIG. 4) that extend to the outer periphery or cylinder jacket area of ​​the housing 20.

[0061] The product lines 34, 35, in particular the second product line 35, can have branches. Furthermore, their geometry (curvature, contour shape, diameter, cross section, etc.) can be optimized taking into account the desired filling mode, in particular free jet filling and wall filling. Usually, no fluid exchange takes place between the first product line 34 and the second product line 35 in the filling device 10, but this is not impossible in principle.

[0062] The upper valve portion 30 further includes a valve rod 36 extending longitudinally through the center of the housing 20. The valve rod 36 is coupled at an upper end to an actuator 37 configured to raise and lower the valve rod 36, and thus a valve cone 51 located at the lower end. The valve rod 36 preferably includes a gas channel 36a extending longitudinally through its center.

[0063] The combination filling valve described above integrates two filling processes, in particular free jet filling, particularly suitable for still filled products, and wall filling, particularly suitable for carbonated filled products, in one filler 10 without compromising the quality of the other filling process. The product contact profile inside the filler 10, including the first product line 34 and the valve cone 51, allows the generation of a first filling jet, in particular a free jet for introducing the filled product into the container. The product contact profile in the jacket area of ​​the filler 10, including the second product line 35, allows the generation of a second filling jet, in particular a rotating filling jet for wall filling, for introducing the filled product into the container.

[0064] The filler 10 can be at least partially produced by additive manufacturing methods. Additive manufacturing methods are useful because, due to the complex channel geometries described above, the production of the entire filler 10 is not possible or only possible at high cost in conventional ways. The channels can be optimally designed in terms of fluid technology, allowing a great deal of design freedom for the implementation of geometries that were previously difficult to realize. In addition, additive manufacturing allows material savings, since, unlike subtractive manufacturing methods, essentially only the necessary material is used.

[0065] For at least partially additively manufacturing the filler 10, in particular the upper valve part 30 and / or the lower valve part 50, a system 100 is used comprising an additive manufacturing device 110 and a control device 150. FIG. 2 shows, in a schematic way, such a system 100 for at least partially additively manufacturing a part 116, in particular the filler 10. The system 100 described herein is based on the principle of "selective laser melting" (SLM). However, the system 100 can also realize other additive manufacturing techniques, such as, for example, "electron beam melting", "laser direct deposition", "metal powder jetting", "wire arc additive manufacturing", "fused deposition modeling", "binder jet" or "nanoparticle jet".

[0066] The additive manufacturing apparatus 110 illustrated herein has a powder feed section 120 and a model section 130.

[0067] The powder feeding section 120 is configured to transfer the powder material 112 layer by layer to the building section. For this purpose, the powder feeding section 120 includes a powder lift unit 122 on which the powder material 112 can be placed and raised and lowered together with the powder material 112. The powder lift unit 122 can be formed in a piston shape, as shown in FIG.

[0068] The additive manufacturing apparatus 110 further comprises a layer creator 124, which is configured to transfer a quantity from the powder material 112 in the powder feeding section 120 to the build section 130 where it creates a worked layer 114 from the powder material 112. This can be done by the layer creator 124 removing an upper layer of the powder material 112 in the powder feeding section 120 and moving it to the build section 130. The layer creator 124 can be formed as a sphere, as in this embodiment, or alternatively as a scraper.

[0069] Thus, the powder material 112 is laid down layer by layer on the base plate 132 of the build section 130. The base plate 132 together with the at least partially processed powder material 112 can then be raised and lowered like the powder lift unit 122, so that the currently processed layer 114 always has a constant distance with respect to the scanner 142 of the beam melting system 140.

[0070] Besides the scanner 142, the beam melting system 140 comprises a laser 144, which is set such that a laser beam 146 locally melts the powder material 112 in the working layer 114 of the building section 130, whereby the material is deposited on the layer located below. The base plate 132 is then lowered by one layer thickness and the new working layer 114 is laid down in the building section 130 by the layer creator 124. The beam melting system 140 then performs a new exposure process. In this way, the additively manufactured part 116 is built up layer by layer.

[0071] Various metals, in particular stainless steels, preferably stainless steel 316L, but also other metals and alloys, such as titanium or aluminum, are conceivable as the source of the powder material 112. The material is applied in powder form to the base plate 132 in a thin working layer 114, preferably with a thickness of 10-100 μm.

[0072] The beam melting method described above is configured with various process parameters, such as the laser power, scan speed, and track spacing of the beam melting system 140 and the layer thickness of the working layer 114 created by the layer creator 124 .

[0073] A scanning procedure in which a beam melting system 140 scans a processing layer 114 or part 116 to be additively manufactured such that so-called "hatching," referred to herein as hatched regions 117, and contour regions 118 are formed is common.

[0074] 3A shows a schematic cross-section of an exemplary part 116 having a hatched region 117 and a contour region 118 that has a simple contour, i.e., contains only one contour line. The hatched region 117 and the contour region 118 are usually performed with different process parameters, for a good compromise between economy and quality, the hatched region 117 being preferably scanned or exposed faster, i.e., at a higher scan speed, than the contour region 118. However, alternative or additional process parameters, such as, for example, laser power or track spacing, can be changed to process-technically differentiate the contour region 118 from the hatched region 117. In this specification, the process parameters applied for the hatched region 117 will be referred to as "hatch process parameters" and the process parameters applied for the contour region 118 will be referred to as "contour process parameters".

[0075] The system 100 further comprises a post-processing system 200, which is set up to post-process the part 116 additively manufactured in the manufacturing device 110, so that the part 116 is better suited for use in the food industry. In particular, the product contact surfaces, such as for example the inner walls of the product lines 34, 35 of the filler 10, are aimed to have a roughness of Ra≦0.8 μm. The post-processing system 200 is based on conventional technologies (abrasive flow machining, Hirtisieren, MMP, DLyte, HIP, etc.).

[0076] The beam melting method and its parameterization are executed by a control device 150, which communicates with the additive manufacturing device 110 and the post-processing system 200, in particular with the various devices and assemblies of these devices and systems, etc. The control device 150 is signal-technically connected to the components to be open-loop or closed-loop controlled and / or read, and thus in particular to the powder supply section 120, the layer creator 124, the build section 130, and the beam melting system 140, and possibly to the post-processing system 200.

[0077] The communication between the control device 150 and the components to be open-loop or closed-loop controlled and / or read can be wired or wireless, digital or analog. The control device 150 can correspondingly receive and / or transmit signals (control signals, data, etc.), and in this regard, both unidirectional and bidirectional signal transmissions are included in the term "communication". In this case, the control device 150 does not necessarily have to be realized by a central computing device or electronic controller, but includes distributed and / or multi-stage systems, control networks, cloud systems, etc. Furthermore, the control device 150 can be an integral part of or communicate with a higher-level equipment control. The control device 150 can also communicate with lower-level equipment control, i.e., the control assigned to the corresponding equipment.

[0078] In order to achieve a high quality and homogeneous surface of the product contact portion of the part 116, various measures described below can be implemented individually or in combination. According to the embodiment of Fig. 3B, all or selected contour areas 118 having multiple adjacent contour lines 118a are scanned. In other words, the control device 150 sets the contour process parameters for the contour area 118, which generates multiple contour lines 118a.

[0079] In an alternative form of additive manufacturing, the contour region 118 is exposed several times, which produces this contour region with higher quality. Fig. 3C shows, as another example, a contour region 118b produced from a combination of shaping of a number of contour lines 118a and several exposures. By exposing the contour line 118a several times, and in particular the contour line intermediate regions, the corresponding parts are newly exposed with adapted parameterization. These regions are thereby newly melted, which makes it possible to achieve qualitatively higher-value compounds in the tissue.

[0080] In this way, the discontinuous transition area between the hatched area 117 and the contour area 118 is transferred to the inside of the part, thereby eliminating the risk that, when the part 116 is further processed, the contour area 118 is partially completely removed, exposing the hatched area 117, which is usually of lower quality than the product-contact surface. Furthermore, possible multiple exposures eliminate bonding defects in the intermediate area. Overall, therefore, a reduction in the number and size of pores in the area near the edge, i.e., on the product-contact surface of the part 116, is achievable.

[0081] A development of the above concept is based on the fact that no distinction is made between hatched regions 117 and contour regions 118. In this case, part 116 is printed without contour regions 118, and control device 150 produces hatched regions 117 with contour process parameters. Control device 150 can also be a machine control device here. In this way, the occurrence of a large number of pores that may possibly occur in the transition region between hatched regions 117 and contour regions 118 can be eliminated, thereby producing a substantially pore-free near-surface structure.

[0082] An alternative or additional measure to improve the surface quality of the product-contact surface of the component 116 is to use a relatively thin layer thickness of the working layer 114 in combination with a fine powder material 112. Conventionally, a powder material with a particle size distribution of about 25-45 μm is used for a working layer thickness of about 50 μm, but the surface roughness can be further reduced by applying a finer powder material 112 with a particle size of up to 20 μm, preferably less than 15 μm, in combination with a layer thickness of up to 20 μm, preferably less than 15 μm. Particularly preferably, the layer thickness of the working layer 114 corresponds substantially exactly to the particle size of the powder material 112, whereby the layer creator 124 creates the working layer 114 with a particle thickness.

[0083] An alternative or additional measure to improve the surface quality of the product-contact surface of the component 116 is to combine different post-processing methods. The post-processing therefore preferably comprises a roughing process, in which a coarse material removal is performed, and a finishing process, which produces the final surface. For this purpose, it is possible to combine an abrasive flow process with the MMP process or the Hirtsisieren or DLyte process, in a sequence adapted to the result to be achieved.

[0084] Alternatively, the additive manufacturing method can be based on a hybrid method, in which a layer-by-layer additive build-up, for example by the additive manufacturing device 110, is combined with sequential downstream subtractive post-processing. The system 100 can comprise a subtractive processing device 160, for example in the form of a milling machine, which is set to abrasively machine the geometry of the part 116 in the current processing stage after the exposure of one or more processing layers 114 by the beam melting system 140. In other words, according to the number of additive build layers individually defined in the additive manufacturing device 110, a tool change is made to the subtractive processing device 160, preferably a milling head. The milling head then mechanically post-machines the geometry created so far. This process is repeated until the part 116 is completely built up.

[0085] By combining such hybrid methods with post-processing, powder residues, welding splashes and tool change step angles can be removed or homogenized, preferably hybrid DED or hybrid SLM methods are combined with abrasive flow machining or Hirtisieren.

[0086] In a hybrid method, subtractive processing during additive manufacturing can result in corners or other surface defects in the part 116. These can be minimized by optimizing the cutting edge geometry of the subtractive processing device 160, for example by using cutting edges with rounded edges instead of sharp cutting edges. Alternatively or additionally, simulation-assisted distortion compensation can be performed to prevent distortions caused, for example, by thermally induced internal stresses during the additive build process and by release of internal stresses in post-subtractive processing.

[0087] In general, additively manufactured parts 116 used in a filling or packaging installation in direct or indirect contact with food can be processed by the method and system 100 in the above-mentioned variants in such a way that they meet hygiene requirements in the food sector. To such parts belong in particular the components of the filler 10, preferably the housing members having product lines 34, 35 or channels of complex geometry.

[0088] 4 is a three-dimensional view of the lower valve portion 50 of the filler 10 (see FIG. 1). The lower valve portion 50 includes the above-mentioned product lines 34, 35, the second product line 35 being formed in the form of a number of jacket channels 35a. The jacket channels 35a are integrated into the housing 20 or into its wall and extend in a spiral manner downwards towards the outlet or opening of the valve portion 50, whereby the jacket channels 35a form a twist for rotating the filled product as it exits the valve portion 50.

[0089] The lower valve part 50 is particularly suitable for the additive manufacturing concept described herein due to its relatively complex channel structure. However, the manufacturing concept is not limited thereto. Other additive manufacturing components are possible in the field of food processing, such as torsion bodies, valve rods, valve cones and other valve closure bodies, metering valves, valve blocks, switching valves in filling technology, water treatment and spraying machines, shells and base caps in stretch blow molding technology, drawing rods with process air channels inside, components for bottle interior coating (e.g. electrodes), filters and sieves, agitators, and mixers and dispensers, possibly with channels or guide vanes, and other fluid-guiding components such as nozzles, channels, lines and tubes that are used to convey, mix and distribute liquid foods or fluids in direct and / or indirect contact with the product.

[0090] The additive manufacturing described herein allows a great deal of design freedom to implement complex geometries that were previously not possible or could only be realized at a very high cost. In particular, seal points and dead volumes based on constructional constraints can be eliminated or avoided, which are not always possible with traditional manufacturing techniques. Functional integration, for example by reducing the number of parts and avoiding seal points, also contributes to this. Furthermore, the design freedom of additive manufacturing can be used to improve the hygienic properties of the part 116, for example by a flow-optimized design.

[0091] Additive manufacturing contributes to material savings since subtractive processes that may possibly be performed are used only for post-processing and are therefore less critical, thereby substantially only using the material required for part 116.

[0092] By precisely adapting the process parameters such as laser power, laser speed, hatch spacing, layer thickness and powder (fine powder) particle size distribution, the part quality can be significantly improved. This improvement can then include a reduction in the porosity (number and size of pores) of the part 116. Possible downstream abrasive post-processing ensures that pores are not exposed, so that an overall reduction in surface roughness can be achieved. The improved as-built surface quality achievable thereby exhibits at least an improved initial roughness for post-processing, if it does not yet meet hygiene requirements.

[0093] Thus, hygienic internal surfaces with a roughness of Ra≦0.8 μm and even high-gloss surfaces with Ra<0.2 μm can be achieved, especially when applying the MMP method, thereby reducing the risk of microbial contamination of the component 116 and improving cleanability.

[0094] Wherever applicable, all individual features shown in the examples can be combined with one another and / or substituted without departing from the scope of the invention. [Explanation of symbols]

[0095] 10 Filler 20. Housing 30 Upper valve part 31 First product connection 32 Secondary Product Connection 33 Gas connection 34 First product pipeline 35 Second product pipeline 35a Jacket Channel 36 Valve rod 37 Actuator 36a Gas Channel 40 Flange part 50 Lower valve part 51 Valve Cone A system for additive manufacturing of 100 parts 110 Additive Manufacturing Equipment 112 Powder materials 114 Processing layer 116 Additively Manufactured Parts 117 Hatch Area 118 Contour Area 118a Contour line 118b A contour area having multiple contour lines and exposed multiple times 120 Powder Feed Section 122 Powder Lift Unit 124 Layer Creation 130 Modeling Section 132 Base Plate 140 Beam Melting System 142 Scanner 144 Laser 146 Laser Beam 150 Control device 160 Removal processing equipment 200 Post-processing system

Claims

1. A method of additively manufacturing a part (116), in particular a part (116) for use with food products, by an additive manufacturing apparatus (110) having a modeling section (130) and a beam melting system (140), the method comprising: building a working layer (114) from a powder material (112), preferably a metal powder, in the building section (130) of the additive manufacturing device (110); exposing the working layer (114) by the beam melting system (140), whereby the powder material (112) of the working layer (114) is locally melted, the beam melting system (140) scanning and exposing the working layer (114) in such a way that at least one hatch area (117) of the additively manufactured part (116) is formed by applying hatch process parameters and at least one contour area (118) is formed by applying contour process parameters, the hatch process parameters and the contour process parameters being preferably at least partially different; A method, wherein in said at least one contour area (118) a plurality of adjacent contour lines (118a) are generated and / or said at least one contour area (118) is at least partially exposed several times.

2. 2. The method according to claim 1, characterized in that in the at least one contour region (118), a plurality of adjacent contour lines (118a) are generated, intermediate spaces of the contour lines (118a) are preferably newly exposed with process parameters changed relative to the contour lines (118a) and / or overlaps of the contour lines (118a) are generated.

3. 3. The method according to claim 1 or 2, characterized in that said at least one hatched area (117) is exposed applying said contour process parameters.

4. 10. The method according to any one of the preceding claims, characterized in that a fine powder having a particle size of at most 20 μm, preferably less than 15 μm, as powder material (112) is applied in combination with a layer thickness of the working layer (114) of at most 20 μm, preferably less than 15 μm, said layer thickness of the working layer (114) being preferably greater than the particle size of the powder material (112).

5. A method of additively manufacturing a part (116), in particular a part (116) for use with food products, by an additive manufacturing apparatus (110) having a modeling section (130) and a beam melting system (140), the method comprising: building a working layer (114) from a powder material (112) in the build section (130) of the additive manufacturing device (110); exposing the working layer (114) to light by the beam melting system (140), whereby the powder material (112) of the working layer (114) is locally melted; A method in which a fine powder having a particle size of at most 20 μm, preferably less than 15 μm, is applied as powder material (112) in combination with a layer thickness of the working layer (114) of at most 20 μm, preferably less than 15 μm, said layer thickness of the working layer (114) being preferably greater than the particle size of the powder material (112).

6. 10. The method of any one of the preceding claims, characterized in that the steps of modeling and exposing the processing layer (114) are performed several times in a continuous process, whereby the additively manufactured part (116) is built up layer by layer.

7. 10. The method according to any one of the preceding claims, characterized in that the exposure of the working layer (114) is followed by subtractive machining of the contour area (118) by a subtractive machining device (160), preferably comprising a milling machine.

8. A method for manufacturing a part (116), in particular a part (116) for use with food products, said method comprising the steps of: Additively manufacturing said part (116) by an additive manufacturing apparatus (110) preferably according to any one of claims 1 to 7; The method includes post-processing at least one surface of said component (116) by one or more post-processing methods, preferably including abrasive flow machining and / or Hirtisieren and / or MMP and / or DLyte and / or HIP.

9. 9. The method according to claim 8, characterized in that at least two post-processing methods are combined, whereby said post-processing comprises a roughing process, in which a rough material removal is performed, and a finishing process, in which a final surface is produced, preferably combining an abrasive flow process with an MMP process or a Hirtisieren or DLyte process, in a sequence adapted to the result to be achieved.

10. A system (100) for additively manufacturing a part (116), in particular a part (116) for use with food products, said system (100) comprising: an additive manufacturing apparatus (110) comprising a build section (130) for building a working layer (114) from a powder material (112), preferably a metal powder, and a beam melting system (140) capable of exposing said working layer (114) to light, thereby locally melting said powder material (112) of said working layer (114); a controller (150) in communication with the additive manufacturing device (110) and configured to cause the beam melting system (140) to scan and expose the working layer (114) to apply hatch process parameters to form at least one hatch region (117) of the additively manufactured part (116) and to apply contour process parameters to form at least one contour region (118), wherein the hatch process parameters and the contour process parameters are preferably at least partially different; The control device (150) is configured to cause the beam melting system (140) to generate a plurality of adjacent contour lines (118a) in the at least one contour region (118) and / or to expose at least a portion of the at least one contour region (118) multiple times.

11. The system (100) of claim 10, characterized in that the control device (150) is configured to cause the beam melting system (140) to generate a plurality of adjacent contour lines (118a) in the at least one contour region (118) and to newly expose intermediate spaces of the contour lines (118a), preferably by changing process parameters for the contour lines (118a) and / or by overlapping the contour lines (118a).

12. 12. The system (100) of claim 10 or 11, wherein the controller (150) is configured to cause the beam melting system (140) to apply the contour process parameters to expose the at least one hatched area (117).

13. The system (100) of any one of claims 10 to 12, characterized in that the additive manufacturing device (110) has a subtractive machining device (160), preferably including a milling machine, and the control device (150) is configured to perform subtractive machining of the contour area (118) by the subtractive machining device (160) following exposure of the machining layer (114).

14. An assembly for manufacturing a part (116), in particular a part (116) for use with food products, said assembly comprising: A system (100) for additively manufacturing a part (116), preferably according to any one of claims 10 to 13, a post-processing system (200) for post-processing at least one surface of said component (116) by one or more post-processing methods, preferably including abrasive flow machining and / or Hirtisieren and / or MMP and / or DLyte and / or HIP; An assembly comprising:

15. Assembly according to claim 14, characterized in that the post-processing system (200) is set up to combine at least two post-processing methods, whereby the post-processing comprises a roughing process, in which a rough material removal is performed, and a finishing process, in which a final surface is produced, the post-processing system (200) being preferably set up to combine an abrasive flow process with an MMP process or a Hirtisieren or DLyte process, in a sequence adapted to the result to be achieved.

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