Method and device for removing resin adhering to additively manufactured components

Abstract

A method for at least partially removing at least partially unreacted resin 10 adhering to a component 1 manufactured using a lithographically generated manufacturing process, comprising the steps of: a) loading at least one component 1 into at least one optionally closable container 3; b) placing the container 3 in one of several receiving positions of a centrifuge 7, 8 eccentric to a rotation axis 6; c) centrifuging the at least one container 3 using a heatable centrifugation device 7, 8, thereby detaching the adhering at least partially unreacted resin 10 from the component 1; and d) collecting the detached resin in an optionally removable collection portion 12 of the at least one container 3.

Description

[Technical field]

[0001] The present invention relates to a method and device for at least partially removing at least partially unreacted resin adhering to components manufactured using lithographically generated manufacturing processes. [Background technology]

[0002] Typically in radiation-cured additive manufacturing processes at process temperature, a liquid or viscous reactive resin is exposed locally and at high resolution to radiation and thereby hardened. A first layer is cured on a build platform or substrate, to which a three-dimensional object can be attached, which is then cured in the form of multiple layers. The additive manufacturing of the object can be performed in a bottom-up or top-down process. Examples of radiation-cured additive manufacturing processes are stereolithography, digital light processing (DLP), two-photon lithography, inkjet, volumetric 3D printing and combinations of the various methods. In addition, the techniques and method combinations can be combined with additional techniques, such as other generative manufacturing processes, fused deposition modeling, subtractive processes, fiber placement systems, fiber coating devices, drilling devices, soldering devices, die coating systems, die bonding equipment, low and high temperature plasma processing devices, wire bonding devices, spray coating and micro-droplet systems, casting equipment, such as for filling components, cutting and milling devices, pick and place units such as robotic arms and many other object manipulators, etc. Another method is a high temperature lithography technique developed by the applicant, where viscous, highly viscous, solid and / or highly filled resins are non-selectively or selectively heated at room temperature, thereby reducing their viscosity until the resin can be processed for the deposition method.

[0003] Even if the printing of 3D geometries is successfully completed, they are still contaminated by reactive resin residues, which may result in a total amount of residual resin being present at least on the surface and / or in cavities of the printed object, in undercuts and in the fine details of the object, with capillary action. Removal of the unwanted residual resin is usually performed in an immersion bath using an organic solvent. The solvent completely dissolves the residual resin adhering to the 3D printed structure, thereby removing more or less the residual resin from the crosslinked photopolymer compound. The solvent can only absorb a small amount of resin, and the cleaning performance may be highly dependent on the load of the resin residue on the solvent.

[0004] More recent approaches in cleaning resin compounds are based on the use of centrifugation techniques (US Pat. No. 10004578, WO 2019 / 209732, US 2021 / 237358). In this case, the separated resin may be subsequently reused, thereby reducing the total amount of chemical waste and the total amount of resin per compound required for the production process, thus reducing production and disposal costs. This also indirectly contributes to resource and environmental protection.

[0005] Also known are approaches for heated and vacuum centrifuges, but these necessitate heating or vacuuming the entire centrifuge chamber, which inevitably requires a larger volume, leading to increased energy costs and longer process times. An additional problem concerns the load distribution in the rotation process: the loads of the centrifuge need to be carefully planned, since a load distribution as uniform as possible in the rotating drum or on the circumference is essential for the non-destructive operation of the centrifuge. The design freedom of the production process and the high degree of individualization of the additively manufactured components inevitably result in a variety of geometries, resulting in different masses or loads. As a result, a uniform load distribution in the centrifuge is practically difficult to achieve, which can lead to significant adoption problems.

[0006] In addition, this problem becomes more acute when centrifuging various printed components, especially when print batches of viscous and / or highly filled resins made of different materials are to be cleaned simultaneously. Standard lithography resins usually have a relatively low viscosity below 2 Pa·s at room temperature, so identical cleaning results can be expected for centrifugal cleaning. On the other hand, for viscous and / or highly filled resins, higher temperatures are usually used for successful cleaning, in order to force a decrease in the resin viscosity and, as a result, to improve the cleaning performance. For various components made of different resins, it is often impossible to find a common temperature that provides satisfactory cleaning results for all possible resins. Furthermore, the strength of the components to be cleaned also plays an important role. As is known, the strength decreases with increasing temperature, which can lead to irreversible component deformation and even component damage during cleaning using rotational movements. This complicates the simultaneous cleaning of components made of different resins and of different 3D print batches.

[0007] In additive manufacturing, this situation is common, but in integrated logistics, printing times per order, component or component batch can vary by orders of magnitude in additive processes, and especially in lithography processes where cleaning of components should be done quickly after the printing process. In particular, in recycling centrifuged resin residues, mixing multiple printing materials makes this situation even worse, resulting in a complete failure to reuse such residual resin volumes. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 10004578 [Patent Document 2] International Publication No. 2019 / 209732 [Patent Document 3] US Patent Application Publication No. 2021 / 237358 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the present invention aims to improve the centrifugation process and, as a consequence, reduce energy costs and extend throughput times while ensuring efficient separation and improved preparation for recycling of the residual resin. [Means for solving the problem]

[0010] To this end, according to a first aspect of the invention, there is provided a method for at least partially removing at least partially unreacted resin adhering to a component manufactured using a lithographically generated manufacturing process, comprising the steps of: - loading at least one component into at least one optionally closable container; - placing the container in one of several receiving positions of the centrifuge and / or the rotating device, eccentric to the axis of rotation; - centrifuging at least one container using a centrifugation device, thereby separating the adhering at least partially unreacted resin from the components; - collecting the detached resin in an optionally removable collection portion of at least one container.

[0011] The invention is therefore based on the idea of ​​providing at least one container in which at least one resin-contaminated 3D printing component can be taken in through an opening, optionally fixed and optionally closed. In this case, the component can be taken in the container as an individual part and fixed in a specific receptacle or attached to a component carrier, in particular a build platform. When fixing the component in a specific receptacle, for example existing holes in the geometry of the printed component can be used to fix the component with screws. When placing the component on the component carrier, a print plate, a print surface or an existing component on which the structure produced in at least one lithographic production is placed and / or printed can be used as the component carrier. Ideally, the build platform is fixed to one of the walls of the container. The wall facing away from the rotation axis is ideally designed to be able to receive the centrifuged resin and convey it to a collection part, such as a resin collection basin, preferably located on the ground. After the at least one container has been loaded and optionally closed, it can be heated and / or evacuated as necessary.

[0012] Alternatively or additionally, according to a preferred embodiment of the invention, the centrifuge chamber of the centrifuge device can be heated, preferably with a heating device comprising a compressor and / or fan unit and a heating element, whereby heated air can be circulated. This is particularly advantageous when working with open vessels. It is also possible to take in various gases, liquids or liquid vapors. It is to be understood that the centrifuge chamber is the chamber enclosed by the housing of the centrifuge device, which contains the vessel.

[0013] Preferably, the container is provided with holes to ensure optimal flow of fluid within the container.

[0014] The container or containers in the centrifuge may then be fixed to a rotor or rotor platform, and the temperature, vacuum conditions, etc. in the centrifuge chamber or inside the container may optionally be controlled. This is followed by a circular movement of the container about the axis of rotation of the centrifuge device, which results in the separation of the resin from the component surface into the container. Typical rotation speeds are in the range of 50 to 5000 revolutions per minute, preferably in the range of 300 to 2000 revolutions per minute. Optionally, additional rotational and / or pivotal movements of the container about one or more axes of rotation occur, which may occur inside and / or outside the container and may be combined with such axial conditions. The remaining residual resin is collected by the walls of the container or the lining of the container facing away from the axis of rotation and is collected in the collection section, i.e. in the volume of the container provided for collection. The inner lining of the container is particularly suitable, for example, a fluorinated polymer such as PTFE or FEP, but also metals such as aluminum or aluminum alloys.

[0015] A further major advantage of the present invention is that the components to be cleaned can be directly loaded into containers while still on the build platform. These containers can be quickly and easily separated from the rotor. This ensures fast loading and unloading of the centrifuge and makes it possible to avoid the more time-consuming and laborious direct removal of the components from the rotor. This leads to a significant reduction in process times as well as an optimization of the centrifuge utilization in daily production.

[0016] The invention is further based on the idea of ​​dividing the total available volume of the centrifugation device into smaller areas arranged around the axis of rotation and spaced apart from one another in the circumferential direction. The invention therefore allows in each case one container or several containers to be arranged in one of several receiving positions of the centrifugation device, which are eccentric with respect to the axis of rotation. The total volume of the centrifugation device available for receiving components is thus formed by the sum of the volumes of the containers, a receiving position being provided for each container. In this case the containers can preferably be fixed in a positive-locking manner to the rotor of the centrifugation device at the respective receiving position. Providing several containers instead of a single centrifugation volume increases the adaptability and allows individual adjustment of the method parameters, as will be explained in more detail below.

[0017] In the case of highly viscous resins, the separation is generally greatly improved, especially supported by the supply of heat. As already mentioned, increasing the temperature reduces the viscosity of the adhering residual resin and promotes its separation from the components. This can be done, among other techniques, by supplying heat to the entire centrifuge chamber. The heat supply can be introduced into the centrifuge chamber by means of convection or radiation. A compromise between viscosity and strength with respect to temperature has to be found individually for each material / resin system, since the increased temperature simultaneously reduces the mechanical strength of the components, which can lead to irreversible deformation or damage of the components during centrifugation. This makes it extremely difficult, for example, to clean two, three or four resin systems simultaneously in a centrifuge. Here, heatable containers offer an optimal solution, if the temperature is individually adjustable for each container, as in the preferred embodiment of the invention. Furthermore, small containers compared to the total volume of the centrifuge are of great advantage, since the heating times and energy costs incurred in a small volume of the container are significantly smaller. Correspondingly, optional insulation of the heated container is also advantageous.

[0018] In addition, the centrifuged residual resin is collected in a container, which prevents resin contamination in the centrifuge and thus increases the throughput time. As a result, containers of different components and resins can also be centrifuged simultaneously. A screen or filter installed in such a container prevents any detached support structures from entering the collection section. An optional vacuum connection serves to degas the resin collected in the collection section during centrifugation, or at least to prevent the entrapment of air or gas in the resin and resin foam. Especially in the field of production of medical or medical technical components, the use of such contamination-free centrifugation units is essential, and for example the collection of residual centrifuged resin volumes in a sterilizable receiving container is the only opportunity to make it possible to reuse such resin volumes for production.

[0019] Another major advantage is therefore the possibility of a rapid change of material without contamination with other resins. For example, assuming that four different containers with four different materials are fixed respectively, cleaning can be carried out simultaneously at four different temperatures and / or pressures in the same centrifuge. In an alternative embodiment, the centrifuge can dynamically support a dynamic heating and / or also a degassing and / or a submersion of the containers. For this purpose, electrical and / or pneumatic and / or mechanical connections can be provided, and the atmosphere of the container can also be indirectly adjusted by placement or introduction into a heated and / or degassed receiving zone. Alternatively, such containers can also be filled and / or submerged with a defined gas, for example a protective or reactive gas.

[0020] If a uniform mass distribution in the centrifuge is not possible, which is the rule rather than the exception in additive manufacturing, due to the mass of the currently cleaning components or build plate, such a uniform mass distribution can be achieved by introducing a balancing weight into the centrifuge. The rotation of the balancing weight represents the "dead mass" in the sense of the energy efficiency of the method. In certain cases, the introduction of a balancing weight is necessary to ensure the smooth operation of the centrifuge. The uniform distribution can be determined by weighing, and a scale may be installed in the centrifuge.

[0021] In a particular embodiment of the invention, the container has closable openings (holes) at different heights (in the z-axis) through which the centrifuged resin can escape from the container or be pushed out (generally radially) by the centrifugal force. By drilling suitable holes in the container, the height of the resin outlet from said container can be controlled in the centrifuge. The resin channels circulating in the centrifuge are arranged at different heights (in the direction of the rotation axis). As a result, containers with different filling states can also be separated indirectly via the centrifuge itself. An additional advantage of this embodiment is that the resin containers can be preheated or heated individually, while the degassing can be done centrally via the centrifuge, and is therefore very practical.

[0022] In a simpler embodiment of the invention, at least one container can also be designed without a lid and / or with a non-removable resin collection section. Furthermore, it can be beneficial to insert holes or openings in certain areas of the container to ensure optimal circulation. This can result in a faster fluid circulation when hot air or hot gas is taken in, which reduces the process time. It is also advantageous to circulate the hot air or hot gas in a closed circuit to reduce the turnover time and keep the energy costs low, but to increase the safety of the operation with regard to the leakage of chemically contaminated gases.

[0023] In an alternative embodiment, at least one container is designed to be rotatably mounted about one or more defined additional rotation axes, which can be located both inside and outside the container or in any other desired combination. In addition to the rotational movement of the centrifuge rotor in the centrifuge, the container can thereby perform additional rotational and pivotal movements. Alternatively, at least one component or component carrier can also be rotatably mounted inside the container, while the container itself can remain stationary on the rotor. In both cases, there are various load change profiles, especially load change speeds. This is particularly important against the background that additively manufactured components withstand very different G-forces, that these G-forces are direction-dependent depending on the material and geometry, that cavities and undercuts may exist in the additively manufactured components, and that it seems advantageous to change the load multiple times for the application of the resin residue. In such cases, depending on the embodiment, it is advantageous if the container can perform purely passive rotational and pivotal movements, which result from the rotation profile and the load or mass distribution of the container itself, or if such additional axial movements (rotation, pivot) are performed by a dynamic drive mechanism of the container carrier in the centrifuge or by specific interference between the container and the centrifuge.

[0024] In a particular embodiment of the invention, the resin collected in the collection section can be closed with a lid after the centrifugation is completed and can be homogenized in an intermediate step. Alternatively, the resin can be emptied from the container and optionally homogenized. The homogenization step is particularly advantageous when the resin is filled with fillers, since the stabilization of the fillers can be achieved by the centrifugal force. This also applies to photoresins with low fillers of 0.1-1 wt.%, but in any case it is particularly advantageous for photoresins with a filler content of 1-10 wt.%, and in particular for photoresins with a filler content of 10-95 wt.%, since the difference between the resin density and the filler density, the morphology of the fillers introduced, the general particle size and particle size distribution of the fillers in the resin, as well as the surface chemistry between the resin and the fillers can be decisive during demixing.

[0025] If necessary, the separated resin can be homogenized via various mixing methods, whereby one or more mixing methods can be performed simultaneously or in succession. Alternatively, several batches of separated residual resin can be combined and optionally subsequently homogenized, or mixed with fresh resin and optionally homogenized. The newly obtained photoresin can then be reused for the 3D printing process. It is noted here that especially unfilled resin systems tend to hardly separate in the centrifugation process, and as a result a homogenization step is usually unnecessary.

[0026] Whether the resin collected in the container after centrifugation is reusable can be determined by various analytical methods that control and guarantee the quality of the resin. The traditional method choices for quality control and quality assurance of photoreactive resins are the measurement of resin viscosity, the measurement of the complete cure of the resin, the determination of the particle distribution in the resin, the measurement of opacity, spectroscopy and / or spectroscopic methods. Typical methods for measuring resin viscosity are, for example, flow cups, rotational viscometers, capillary viscometers, falling body viscometers or Melt Flow Index (MFI) measuring instruments. Viscosity is particularly suitable as an indicator of the quality of the resin. For example, partial crosslinking of the resin usually leads to an increase in viscosity, or the stabilization of filler particles leads to a viscosity gradient in the resin.

[0027] One method for measuring full cure is to expose the photoreactive resin to a defined radiation dose or intensity for a specific period of time, which should result in the cure of a thin layer, usually a few hundred to a few hundred microns thick, which can then be measured (e.g., with an external micrometer, optically, electronically).

[0028] The particle distribution can be easily determined, for example, via a grindmeter. The quality control is better the closer the measurement results of the respective method are to those of the starting resin. The limits of possible deviations between the measurement results of the starting resin and the new resin are highly dependent on the respective resin. Significant tolerances are in each case ±5%, ±10%, ±15%, ±20%, ±25% or even higher, based on the respective measurements of the starting resin and the new resin.

[0029] The at least partially unreacted resin to be removed from the component is preferably a photoresin. Photoresins are usually composed of (end-group modified, reactive) oligomers, low molecular weight monofunctional and / or multifunctional reactive diluents, fillers, additives, and / or at least one photoinitiator. Examples of (end-group modified, reactive) oligomers are in principle all polymers, polyaddition and polycondensation products, such as polyethers, polyesters, polyurethanes, polycarbonates, polyamides, polythioethers, polythioesters, silicones, etc. In many cases, the reactive components have one or more reactive end groups that cure upon exposure to radiation of a suitable wavelength upon decomposition of at least one photoinitiator to form a solid crosslinked polymer. Examples of reactive end groups include unsaturated double bonds, vinyls, acrylates, methacrylates, acrylamides, allyl compounds, norbornenes, vinyl ethers, epoxides, oxetanes, maleimides, thiols, to name a few. Typical photoinitiators upon decomposition or activation form radicals, cations, anions, or other active species (e.g., Grubbs' catalysts) that trigger polymerization upon irradiation with specific wavelengths, usually resulting in a crosslinked photopolymer.

[0030] Photoresins can also contain high contents of organic, inorganic, ceramic, and / or metallic fillers to produce hybrid materials after polymerization. The fillers can also be oligomers, prepolymers, and / or polymers. Typical filler contents range from 1 to 95 wt.%. After cleaning, for example, inorganic, ceramic, or metal filled photopolymers can be further processed into ceramics or metals in a debinding and sintering process. In addition, the photopolymers can be composed of a dual cure system, where the first crosslinking for shaping is performed in the 3D printing process and the second crosslinking is triggered in a downstream process, for example by heat.

[0031] The at least partially unreacted resin to be removed from the component is preferably a medium-viscosity level resin having a viscosity of 5 to 30 Pa·s, a high-viscosity level resin having a viscosity of 30 to several hundred Pa·s, or a very high viscosity of 1000 Pa·s or more at room temperature (20°C).

[0032] The method according to the invention is preferably incorporated into a process chain of a manufacturing process. Typically, the process chain includes as a starting step a digital preparation, in which the three-dimensional component to be manufactured is digitally prepared, after which the component is printed in a lithography-based additive manufacturing process. Optionally, one or more optional pre-cleaning steps of the component may then be performed. The component is then cleaned according to the cleaning method according to the invention, and finally in one or more downstream processes the final three-dimensional component is obtained.

[0033] In the digital preparation step, the existing 3D data of the component is optimized and prepared for the printing process according to the specifications of the subsequent production manufacturing process. These processing steps for the 3D model may include, among others, data error analysis, possibly data repair, scaling, positioning of the 3D model on a digital printing platform, geometric compensation for overpolymerization, which occurs for example in radiation curing methods, formation of support geometry, and generation of layer information. All substeps can be performed manually, semi-automatically, or fully automatically. Alternatively, the printing data can also be directly formed in the CAD software according to process-dependent design guidelines including all substeps.

[0034] In a photopolymerization-based printing process, a photoresin is irradiated with localized high-resolution radiation in a lithography-based manner, and the irradiated areas harden to form a solid. The process is performed stepwise or continuously, and a pre-prepared three-dimensional structure is built up. In this case, the components are usually placed on a build platform. The build platform can be present in various embodiments. The build platform can be made of different materials, for example metals, ceramics, plastics, hybrid materials, one composite material or multiple composite materials. The build platform usually has a smooth and flat surface, but uneven surfaces, depressions and / or holes can also be advantageous. Depressions and holes in the build platform can be beneficial for centrifugal cleaning insofar as the resin can be centrifuged from the components through the holes and depressions to the build platform and through the depressions and holes in the build platform by centrifugal forces.

[0035] Build platforms and / or components can be made uniquely identifiable and distinguishable by means of a unique identifier (UID) (e.g., using a chip, barcode, QR code, REID, numbering, NFC, etc.), facilitating identification along the entire process chain, from digital preparation of the part to 3D printing, through post-processing for quality control in the final component, or even installation in the final product.

[0036] After a successful 3D printing process, the component can be completed or refined. These processes are called post-processing and include various downstream processes to obtain the final component properties. Typical post-processing steps are cleaning using centrifugal forces, cleaning with solvents using turbulent flow, directed jets, ultrasound, steam, aerosols and / or pressure circulation processes, cleaning using gas and / or directed gas flows (e.g. compressed air, heated compressed air), drying of the component, post-curing which can be performed in various ways (thermal, radiation-induced, microwave), removal of support structures and coloring, coating (e.g. metal or plastic coating), painting, equipping (e.g. with microchips, pins, cables, electrical contacts) of the 3D printed component. Furthermore, other generative manufacturing processes can be used, such as fused deposition modeling, subtractive processes, fiber placement systems, fiber coating devices, drilling devices, soldering devices, die coating systems, die bonding equipment, low and high temperature plasma treatment devices, wire bonding devices, spray coating and micro-droplet systems, casting equipment for filling components, cutting and milling devices, pick and place units such as robotic arms and many other object manipulators. Where appropriate, all the mentioned post-processing methods can be performed in any order or not at all, simultaneously, consecutively, as many times as desired, and manually and / or semi-automatically and / or fully automatically. In this respect, it should be mentioned that a post-processing step is also optionally performed before the centrifugation cleaning. For example, a solvent cleaning can be performed beforehand and a centrifugation step can be used to separate the residual solvent located on the components.

[0037] After post-processing, the final 3D components are obtained, some examples of which are medical, dental and orthodontic applications, e.g. intraoral applications such as adjusters, aligners, splints or attachments, medical technology products, food industry, electronic components such as plug connectors, connectors, plugs or housings, 3D printed shoe soles, parts for the aerospace industry, applications in the military sector, applications in the consumer goods sector, applications in the mobility sector, automobiles and electric vehicles, 3D printed parts used in the energy sector, e.g. in the sports sector such as shoe soles or cushioning elements, applications in the printed electronics sector, applications in the tool manufacturing sector.

[0038] According to a second aspect, the invention relates to a device for at least partially removing at least partially unreacted resin adhering to a component manufactured by means of a lithographically generated manufacturing process, in particular for carrying out a method, in particular for carrying out a method according to the invention, the device comprising a centrifugation device having a rotor drivable for rotation about an axis of rotation and a plurality of containers each having a container opening provided for loading at least one component and fixing means for fixing at least one component inside the container, the rotor comprising a plurality of receptacles eccentric with respect to the axis of rotation for an eccentric arrangement of each container of the plurality of containers, the containers optionally comprising a closing portion for closing the container opening and an optional collecting portion for collecting the detached resin.

[0039] Preferred embodiments of the device according to the invention are specified in the subclaims.

[0040] The invention will now be explained in more detail with reference to exemplary embodiments shown in the drawings. [Brief description of the drawings]

[0041] [Figure 1a] FIG. 1 shows an embodiment of a centrifugation device with a container in a fixed and secured position. [Figure 1b] FIG. 1 shows an embodiment of a centrifugation device with a container in a fixed and secured position. [Figure 1c] FIG. 1 shows an embodiment of a centrifugation device with a container in a fixed and secured position. [Figure 1d] FIG. 1 shows an embodiment of a centrifugation device with a container in a fixed and secured position. [Figure 1e] FIG. 1 shows an embodiment of a centrifugation device with a container in a fixed and secured position. [Diagram 2] FIG. 1 illustrates an alternative embodiment of a centrifugation device in which components are rotatably mounted relative to a centrifugation platform. [Figure 3a] FIG. 1 illustrates an example of a container placed within a centrifugation device. [Figure 3b] FIG. 1 illustrates an example of a container placed within a centrifugation device. [Figure 3c] FIG. 1 illustrates an example of a container placed within a centrifugation device. [Figure 3d] FIG. 1 illustrates an example of a container placed within a centrifugation device. [Figure 3e] FIG. 1 illustrates an example of a container placed within a centrifugation device. [Figure 4a] 1 shows various geometric options for the walls of the container. [Figure 4b] 1 shows various geometric options for the walls of the container. [Figure 4c] 1 shows various geometric options for the walls of the container. [Figure 4d] 1 shows various geometric options for the walls of the container. [Diagram 5] FIG. 1 shows an exemplary sequence of centrifugation methods. [Figure 6] FIG. 1 illustrates an exemplary reuse cycle. [Figure 7a] FIG. 13 shows alternative possibilities for centrifugation structures. [Figure 7b] FIG. 13 shows alternative possibilities for centrifugation structures. [Figure 7c] FIG. 13 shows alternative possibilities for centrifugation structures. [Figure 8] FIG. 1 shows an example of a container with specially designed walls. [Figure 9] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The drawings referred to in the following description are merely provided for optimal understanding of the present invention and do not constitute limitations of the present invention. The dimensions of the illustrated components can be changed as desired. To facilitate a better understanding of the present invention, only the essential assemblies and parts of the present invention are shown. For example, fastening, connection, and / or translation may be realized in various ways.

[0043] Fig. 1a shows a centrifuge device comprising a stationary outer wall 5, a rotor axis of rotation 6 and a rotor 7 driven to rotate about the rotor axis of rotation. At both ends of the rotor 7, fastening devices 4 are arranged in respective receiving positions for fastening a container 3 to the rotor 7. In the container 3, at least one component 1 is arranged or fixed, which is attached to a build platform 2 and which is manufactured by means of a lithographically generated manufacturing process and which is at least partially covered with unreacted resin which is separated by centrifugation. The build platform 2 together with the component 1 is arranged in the container 3 such that the side of the build platform 2 facing the component 1 faces radially outwards.

[0044] FIG. 1b shows a centrifugation structure similar to FIG. 1a, where the build platform 2, together with its associated component 1, is positioned within a container 3 such that the side of the build platform 2 facing away from the component 1 faces radially outward.

[0045] Figures 1c and 1d show a modified embodiment of a centrifugation device with a rotor platform 8 driven to rotate about a central axis of rotation. The rotor platform 8 has a number of (here two) eccentric receiving positions for receiving in each case one container 3, and in each case one fixing device 4 is provided for placing a container 3 on the rotor platform 8. The term rotor platform does not represent a geometrical limitation of the rotating device.

[0046] In the embodiment of Fig. 1c the container 3 is mounted to the outer wall of the rotor platform 8, whereas in the embodiment of Fig. 1d the container 3 is mounted to the inner wall of the rotor platform. Thus, the build platform 2 together with the component 1 is arranged in the container 3 such that either the side of the build platform 2 facing towards the component 1 (Fig. 1c) or the side of the build platform 2 facing away from the component 1 (Fig. 1d) faces radially outward.

[0047] FIG. 1e shows an alternative embodiment of a centrifugation device having a rotor platform 8 on which one or more containers 3 are fixed, in this embodiment four.

[0048] The components 1 arranged in Figures 1a-1e are optionally printed on a build platform 2 and can be facing the axis of rotation, facing away from the axis of rotation, or fixed in any other manner.

[0049] FIG. 2 shows a centrifugation device with a rotor platform 8, in which a basic rotation about a rotation axis 6 can be superimposed with another rotation about another rotation axis 6a arranged eccentrically with respect to the rotation axis 6. For this purpose, according to a first embodiment, each vessel 3 is arranged stationary with respect to the rotating rotor platform 8, and the respectively associated build platform 2 is mounted rotatably with respect to the vessel 3 about another rotation axis 6a. According to a second embodiment, each vessel 3 is mounted rotatably with respect to another rotation axis 6b, and the respectively associated build platform 2 is rigidly fixed to each vessel 3. In all of the examples shown in FIGS. 1, 2 and 8, the movably mounted assemblies may rotate about one and / or several rotation axes, optionally both clockwise and counterclockwise.

[0050] 3a-3e each show a side view of a vessel 3, where the build platform 2 is fixed to the component 1 within the vessel 3 via a fixing device 9. The centrifugal force (F zf ) can be used to separate the resin 10 from the component 1 and collect in a collection area or resin reservoir 12 at the bottom of the container 3. Ideally, the opposite wall of the component 1 can be optionally angled slightly downwards to facilitate the resin entering the resin reservoir by the centrifugal force. The build platform 2 can be fixed to the fixture device 9 at various angles. In FIG. 3a, the build platform 2 is positioned perpendicular to the centrifugal force. In FIG. 3b, the build platform 2 is tilted slightly upwards compared to the orientation of FIG. 3a, and in FIG. 3c, the build platform 2 is tilted slightly downwards compared to the orientation of FIG. 3a.

[0051] With reference to figure 3c, the container 3 is also provided with a lid 11 so that the container 3 can be closed. Furthermore, the resin reservoir 12 is designed to be removable and can therefore be emptied more easily.

[0052] FIG. 3d shows two build platforms 2 rotatably mounted around another axis of rotation 6a, and a vessel 3 additionally having a permeable filter or screen 13 positioned between the component 1 and the resin reservoir 12.

[0053] 3e shows the case of a resin-permeable build platform 2a, where the resin permeability can be achieved by means of depressions or holes in the build platform 2a, where the resin residue is separated from the component 1 by centrifugal forces onto the build platform 2a and then through the depressions or holes into the optionally removable resin reservoir 12.

[0054] Figures 4a to 4d show, from above, different geometric options for the container wall and the container rear wall, which can be, for example, rectangular, elliptical, trapezoidal or polygonal geometric shapes.

[0055] Figures 5a to 5c describe an example structure of a vessel 3 and an example process flow. Figure 4a shows a vessel 3 fixed to a rotor 7 via a fixing device 4. The rotor 7 contains inside a power supply and / or cables 15, which can for example operate a heater or ensure data transfer, and also contains inside a vacuum line or a gas and / or liquid inlet 16, through which the vessel 3 can be submerged. This rotor 7 can also be a rotor platform 8. In Figure 4a, the vessel 3 with the resinified components 1 is closed with a lid 11 and centrifugal forces (F) are applied on a build platform 2, which is mounted on the vessel wall via build platform fasteners 9. zf) The resin residue 10 is detached from the component 1 by the centrifugal force, is forced through a screen or filter structure 13 and collected in the resin reservoir 12. The screen 13 mainly prevents the detached component or support structure from entering the resin reservoir 12. After the centrifugation process is finished (FIG. 4b), the part 14 from which the resin has been largely removed can be discharged from the centrifuge together with the build platform 2 by opening the container lid 11. Similarly, the resin reservoir 12 filled with resin 10 can be removed from the container 3. In step (c), the cleaned component 14 is sent to a further post-processing sequence and the separated resin residue 12 is sent to a recycle cycle, optionally after closing with a closure cap 17. The container 3 can then be loaded with a new build platform 2 and the component 1 containing resin and the new cleaned resin reservoir 12 can be installed in the container 3.

[0056] Figure 6 shows a possible recycling cycle for the separated residual resin. Here, it is possible to directly mix the separated residual resin with fresh resin and then process the mixture again in the 3D printer. Furthermore, it is also possible to homogenize one or more separated batches of residual resin and then feed them into the 3D printing process, or to mix the homogenized residual resin with fresh resin before returning it to the 3D printer.

[0057] Fig. 7a shows a cross-sectional view of a preferred centrifuge arrangement including a container. In this case, the container 3 is fixed on a rotor platform 8 with the aid of a fastening device 4, which rotates around the rotor axis 6. The outer one of the two fastening devices 4 is preferably fixed along the outer edge of the rotor platform 8 and corresponds to a robust annular structure that holds the container 3 on the rotor plate. The fastening device 4 can also be designed such that the container is fixed at an angle to the rotor axis 6. The outer housing 5 of the centrifuge can be closed with a lid 11a. Optionally, the centrifuge chamber can also be heated, for example with hot air, infrared radiators and / or heating sleeves.

[0058] In an alternative embodiment of the centrifuge configuration (FIG. 7b), the container 3 is placed such that the centrifugal force acting on the component 1 is directed towards the printing surface, e.g. the build platform 2, so that the component 1 faces or is located in the direction of the rotation axis 6. This is particularly preferred if the component 1 is subject to tensile stresses or if a particular component geometry can ensure a favorable resin outflow. The centrifuge chamber, optionally surrounded by the outer housing 5 and the lid 11, can also be heated (e.g. by hot air, infrared radiators, and / or heating collars), evacuated, and / or cleaned with steam or gas.

[0059] FIG. 7c shows a further embodiment of a centrifuge, in which in this case the centrifugation chamber is connected to a compressor and / or fan unit and / or pump unit 16 (e.g. radial or axial compressor) and a heating device consisting of a heating element 17 (e.g. heating cartridge or heating spiral). Possible movements of the air flow 15 are shown. In FIG. 7c the container 3 is designed without a lid and equipped with holes in preferred places, allowing an optimal circulation of the preheated air. As can be seen from FIG. 7c, the preheated air 15 is preferably circulated in the centrifugation process in order to keep the energy input low.

[0060] An example of holes or recesses 18 in the wall 3 of the container to ensure optimal fluid (e.g. air) flow is shown in Figure 8. These are preferably located on the side facing away from the resin collection wall.

[0061] Figure 9 shows a top view of the container 3. The container is designed in such a way that the build platform 2 with the resinified components 1 can be easily inserted into and removed from the container via positive locking rails. The positive locking rails also have the advantage that safety is guaranteed for the user and no additional fixing means are necessary. Alternatively, the build platform can also be provided with lateral grooves, which are then pressed in a positive locking manner into guides provided for this purpose and are thus also locked against the rotation process.

Claims

1. A method for at least partially removing at least partially unreacted resin (10) adhering to a component (1) manufactured using a lithographically produced manufacturing process, comprising the steps of: - loading at least one component (1) into at least one optionally closable container (3); - placing said container (3) in one of several receiving positions of a centrifugation device (7, 8) eccentric to the axis of rotation (6); - centrifuging said at least one container (3) using said centrifugation device (7, 8), thereby separating said adhering at least partially unreacted resin from said component (1); and collecting said detached resin in an optionally removable collection portion (12) of said at least one container (3).

2. 2. The method according to claim 1, characterized in that the at least one component (1) is placed in the container (3) and the at least one component (1) is attached on a component carrier (2), in particular on a build platform.

3. 3. The method according to claim 1 or 2, characterized in that the at least one component (1) or the component carrier (2) is fixed relative to the container (3), preferably on a side or wall of the container (3) facing towards the axis of rotation (6) of the container (3) or towards the centrifugation device (7, 8) or on a side or wall of the container (3) facing away from the axis of rotation (6) of the container (3) or towards the centrifugation device (7, 8).

4. 4. The method according to claim 1, 2 or 3, characterized in that the centrifugation chambers of the centrifugation devices (7, 8) are heated, preferably by a heating device comprising a compressor and / or a fan unit (16) and a heating element (17), whereby heated air is circulated.

5. 5. The method according to any one of claims 1 to 4, characterized in that the container (3) is provided with holes (18) to ensure optimal circulation of fluid within the container (3).

6. 6. The method according to any one of claims 1 to 5, characterized in that the at least one container (3) is closed before centrifugation.

7. 7. The method according to claim 1, wherein the at least one component (1) arranged in the container (3) is heated by means of a heating device before and / or during centrifugation.

8. 8. The method according to claim 1, wherein the loading step comprises placing at least one component (1) in a first container (3) and placing at least one further component (1) in a second container (3), and wherein the heating of the first and second containers (3) is controlled in such a way that a different temperature prevails in the first container (3) than in the second container (3) during centrifugation.

9. 9. Method according to any one of the preceding claims, characterized in that the interior of the container (3) is placed under reduced pressure after closure.

10. 10. The method according to any one of claims 1 to 9, characterized in that the at least one container (3) is rotated, and optionally driven to rotate, during centrifugation relative to a rotor (7, 8) of the centrifugation device carrying the at least one container (3).

11. 11. The method according to any one of the preceding claims, characterized in that the collection portion (12) is separated from the container (3) together with the separated resin (10) disposed therein.

12. 12. The method according to claim 1, wherein the resin (10) collected in the collection portion (12) is returned to the manufacturing process of the lithographic production of a component, preferably undergoing a quality control before returning, said quality control preferably including a viscosity measurement and / or a measurement of complete curing.

13. A device for at least partially removing at least partially unreacted resin (10) adhering to a component (1) manufactured with the aid of a lithographically generated manufacturing process, in particular for carrying out the method according to any one of claims 1 to 12, comprising a centrifugation device (7, 8) having a rotor (7, 8) drivable for rotation about an axis of rotation (6), and a plurality of containers (3) each having a container opening provided for loading at least one component (1) and fastening means (9) for fastening said at least one component (3) inside said container, said rotor (7, 8) comprising a plurality of receptacles eccentric with respect to said axis of rotation (6) for an eccentric arrangement of each container of said plurality of containers (3), said containers (3) optionally comprising a closing part (11) for closing said container opening and an optional removable collecting part (12) for collecting detached resin (10).

14. 14. The device according to claim 13, characterized in that the centrifugation devices (7, 8) comprise heating devices, each of which is assigned to a respective vessel (3) and in that means are provided for individually controlling the heating devices, by means of which the temperature of each vessel (3) can be individually regulated.

15. 15. A device according to claim 13 or 14, characterized in that the centrifugation devices (7, 8) comprise at least one vacuum source, which is in fluid communication with the interior of the container (3) in each case via a controllable closure.

16. 16. Device according to claim 13, 14 or 15, characterized in that the container (3) is mounted on the rotors (7, 8) so as to be rotatable relative to the rotors (7, 8).

17. 17. The device according to claim 13, characterized in that the containers (3) each have a fixing device (9) for fixing the at least one component (1) or a component carrier (2) on a side or wall of the container (3) facing towards the axis of rotation (6) of the centrifugation device (7, 8) or on a side or wall of the container (3) facing away from the axis of rotation (6) of the centrifugation device (7, 8).

18. 18. A device according to any one of claims 13 to 17, characterized in that the containers (3) each comprise a retention device (13), such as a screen or filter, arranged upstream of the collection portion (12).

19. 19. Device according to any one of claims 13 to 18, characterized in that the collecting part (12) is detachably connected to the container (3) and is preferably designed as a collecting trough.

20. 20. A device according to any one of claims 13 to 19, wherein the collection portion (12) is fluidly connected to a side or wall of the container (3) facing away from the rotation axis (6) of the centrifugation device (7, 8), in particular arranged below said side or wall.

21. 21. A device according to any one of claims 13 to 20, characterized in that the collecting part (12) is designed as a collecting trough on the wall facing away from the axis of rotation (6) and provided with at least one closable opening, and that the centrifugation device (7, 8) comprises at least one annular, in particular stationary, collecting channel, which surrounds the circular path of the opening.

22. 22. Device according to any one of claims 13 to 21, characterised in that the centrifugation chambers of the centrifugation devices (7, 8) are connected to a compressor and / or fan unit (16) and to a heating element (17).

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