METHOD FOR PRODUCING A COMPONENT USING A THREE-DIMENSIONAL PRINTING METHOD

Abstract

The present invention relates to a method of manufacturing a component, in particular a component that is used in the manufacture of dental components or a dental component, by means of a three-dimensional printing process, said method comprising the steps: providing a base element: and printing the component in a liquid bath on the base element such that the component has a hollow space after a completion of the printing,
wherein at least one channel is provided that establishes a fluid connection between the hollow space and the environment at least after the completion of the printing. The present invention further relates to a system comprising a printing apparatus for printing a component in a liquid bath in accordance with the method described above.

Claims

1. A method of manufacturing a component by means of a three-dimensional printing process, said method comprising the steps: providing a base element; and printing the component in a liquid bath on the base element such that the component has a hollow space after a completion of the printing, wherein at least one channel is provided that establishes a fluid connection between the hollow space and the environment at least after the completion of the printing.

2. The method in accordance with claim 1, wherein the channel is at least sectionally bounded by the base element.

3. The method in accordance with claim 1, wherein the channel is at least sectionally integrated into the base element.

4. The method in accordance with claim 1, wherein the channel is at least partly produced on the printing of the component.

5. The method in accordance with claim 1, wherein the hollow space is at least sectionally bounded by the base element after the completion of the printing.

6. The method in accordance with claim 1, wherein the channel has at least one wound section, one curved section, and/or one section extending obliquely to a longitudinal axis of the channel.

7. The method in accordance claim 1, wherein a cross-section of the channel varies locally.

8. The method in accordance claim 1, wherein an end of the channel remote from the hollow space has an interface for connecting the channel to a separate fluid system.

9. The method in accordance with claim 1, wherein at least one support structure for increasing the stability of the component and/or at least one guidance structure for selectively guiding fluid is/are provided in the interior of the hollow space.

10. The method in accordance claim 1, wherein at least one of the support structure ands the guidance structure is in connection with the channel.

11. The method in accordance claim 1, wherein at least two channels are provided that are in fluid communication with the hollow space, with the channels being distributed in a peripheral direction of the component, and/or with the channels being arranged in one plane or in different planes, viewed in a printing direction of the component.

12. The method in accordance with claim 1, wherein the printing process is a stereolithography process, a CLIP process (continuous liquid interface production), and/or a hybrid process.

13. The method in accordance with claim 1, liquid of the liquid bath present in the hollow space is removed through the channel after the printing.

14. The method in accordance with claim 1, wherein at least one of a flushing liquid and a flushing gas is introduced into the hollow space through the channel after the printing.

15. The method in accordance with claim 1, wherein the component is dried after the flushing.

16. The method in accordance with claim 1, wherein the component is hardened after a removal of the liquid from the hollow space and/or after the flushing of the hollow space.

17. The method in accordance with claim 1, wherein at least one of the channel and the base element is separated from the component after the printing, after the flushing, after the drying, or after the hardening of the component.

18. A system comprising a printing apparatus for printing a component in a liquid bath in accordance with a method of manufacturing a component by means of a three-dimensional printing process, said method comprising the steps: providing a base element; and printing the component in a liquid bath on the base element such that the component has a hollow space after a completion of the printing, wherein at least one channel is provided that establishes a fluid connection between the hollow space and the environment at least after the completion of the printing.

19. A system comprising a flushing apparatus for flushing a component manufactured using a method of manufacturing a component by means of a three-dimensional printing process, said method comprising the steps: providing a base element; and printing the component in a liquid bath on the base element such that the component has a hollow space after a completion of the printing, wherein at least one channel is provided that establishes a fluid connection between the hollow space and the environment at least after the completion of the printing, wherein the flushing apparatus has a flushing device which can be coupled to the channel of the component and by which at least one of a flushing liquid and a flushing gas can be introduced into the hollow space.

20. The system in accordance with claim 19, wherein the flushing apparatus comprises a flushing chamber in which the component can be arranged, with the flushing chamber having at least one flushing element for applying at least one of a flushing liquid and a flushing gas to the component.

21. The system in accordance with claim 19, further comprising a drying apparatus for drying the component.

22. The system in accordance with claim 19, further comprising a hardening apparatus for hardening the component.

23. The system in accordance with claim 19, further comprising a fixing apparatus for a positionally accurate fixing of the base element in the printing apparatus, in the flushing apparatus, in the drying apparatus, and/or in the hardening apparatus.

Description

[0031] The present invention will be explained in the following purely by way of example with reference to advantageous embodiments and to the enclosed drawings. There are shown:

[0032] FIG. 1 a model manufactured using digital data by means of 3D printing;

[0033] FIG. 2 the embedding of the model;

[0034] FIGS. 3 and 4 a first embodiment of the present invention;

[0035] FIGS. 5 and 6 a second embodiment of the present invention;

[0036] FIGS. 7 and 10 a third embodiment of the present invention;

[0037] FIGS. 9 and 10 a fourth embodiment of the present invention;

[0038] FIG. 11 a fifth embodiment of the present invention;

[0039] FIGS. 12 to 14 a sixth embodiment of the present invention;

[0040] FIGS. 15 to 17 a seventh embodiment of the present invention; and

[0041] FIGS. 18 to 20 a system in accordance with an embodiment of the present invention.

[0042] FIG. 1 shows, by way of example, a model 10 that is used for the manufacture of a dental prosthesis or partial dental prosthesis. In the present example, it comprises three dental prosthesis components 12 that are arranged on hollow cylinders 16 by means of webs 14 in each case. The model 10 is printed on a base element 17 by means of 3D printing. In the present case, the base element 17 is a plate. However, any desired other geometries of the base element 17 are conceivable.

[0043] A suitable printing process is, for example, stereolithography in which a light-curing liquid plastic is hardened in thin layers by a laser. This process takes place in a bath of the plastic. After the hardening of each layer through the irradiation by the laser, the component to be manufactured is lowered by a layer thickness. The liquid plastic disposed above the component is then uniformly distributed by a wiper. Subsequently, the liquid plastic is irradiated by laser light again in order to form the next component layer. The three-dimensional model 10 is gradually created in this manner.

[0044] In the CLIP process (continuous liquid interface production), the component is manufactured continuously. A bath of a light-curing plastic is also present here. However, in this process, a laser beam is directed through a base of the container of the plastic bath, which is transparent for the wavelength used, and is focused precisely where the plastic should harden. The object to be printed is slowly pulled out of the plastic bath by a platform such that the liquid plastic can always flow into the thin intermediate space between the object and the base. The base is designed such that the hardening plastic does not adhere to it.

[0045] Variants and refinements of these processes are generally known. In addition to the aforementioned processes, other 3D printing processes (also hybrid processes) can also be used.

[0046] However, there is the problem with complex model geometries that liquid plastic can collect in undercuts and/or hollow spaces of the model. As has been initially described, this can lead to a deformation of and/or other damage to the model. In the example of FIG. 1, liquid collects in the interior of the hollow cylinders 16 and cannot escape after the completion of the printing process. This can, for example, result in a pressure difference forming between a respective inner space or hollow space 18 of the cylinders 16 and the outer space (e.g. due to an outgassing of the liquid plastic), said pressure difference having a negative effect on the shape of said outer space.

[0047] FIG. 2 shows the step of embedding the model 10 by means of an embedding medium 20. A housing cylinder 22 was placed onto the plate 17 for this purpose.

[0048] After the embedding of the model 10 and the hardening of the embedding medium 20, the printed model 10 is burned out such that a hollow negative mold of the model 10 is formed in the embedding medium 20. The negative mold is now (partly) filled with a raw material for the dental prosthesis components 12 to be manufactured and is subsequently fired. During the firing, an exertion of pressure on the raw material can optionally be provided that is produced by pressure stamps. They are movably arranged in the cylindrical hollow spaces that are created by the hollow cylinders 16 of the model 10.

[0049] The unwanted liquid accumulations described above and associated problems have led to the prejudice that 3D printing processes can be problematic at least in the dental sector in which particular precision is important. It was already possible to provide a remedy in this case through the present invention.

[0050] FIG. 3 shows a hollow cylinder 16 printed on the base element 17 (the components 12 and webs 14 have been omitted for reasons of simplicity). To be able to remove liquid from the interior of the cylinder 16, a channel 24 is provided whose interior is in contact with the hollow space 18 of the cylinder 16. Liquid can thereby drain from the cylinder 16. The channel 24 can also be used to flush the hollow space 18, for example, with a liquid and/or with a gas. The channel 24 also enables a pressure equalization and/or an active or a passive drying of the hollow space 1. An application of fluid to the hollow space 18 can take place at a (small) excess pressure if necessary. An application of an underpressure (fluid suction) is also conceivable.

[0051] FIG. 4 shows a plan view so that it can be recognized that two channels 24 are provided that viewed relative to the cylinder 16 are disposed opposite one another. One of the two channels 24 can serve as an inlet channel for a flushing fluid or drying fluid while the other channel 24 serves as an outlet channel. The hollow space 18 can thus be efficiently flushed through. It is understood that any desired number of channels 24 can be provided.

[0052] In the embodiment shown by way of example, the channels 24 have a semicircular cross-section. In general, any desired cross-sectional shapes, which can also vary in the longitudinal direction of the channels 24 if required, are conceivable.

[0053] The channels 24 can be formed by the printing process and are in particular produced from the same material as the cylinder 16. However, it is also possible that the channels 24 are formed in one piece with the base element 17 and/or can be (partly) integrated into it. The channels 24 are then figuratively speaking “printed around” by the cylinder 16.

[0054] In accordance with a variant of the method, separate channel components in the present example this would then be two channel-like half-shells are provided that are fastened to the base element 17 prior to the printing process. They can be composed of the same material from which the model 10 is printed. However, the selection of other materials is also possible. The same applies to mixed forms of the variants described above.

[0055] The ends of the channels 24 remote from the cylinder 16 each have an opening 28. The channels 24 extend up to the margin of the base element 17 such that the housing cylinder 22 closes the openings 28 on an embedding of the model 10 and consequently no embedding medium 20 can enter the cylinder 16.

[0056] FIG. 5 and FIG. 6 show a further variant of the invention. Here, the channels 24 are not designed in a straight line throughout, but each have a bend 26 of approximately 90° in their course. Moreover, they do not extend up to the margin of the base element 17, Thus, the openings 28 of the channels 24 are indeed exposed on the embedding. However, the bends 26 prevent the comparatively high viscosity embedding medium 20 from entering the hollow space 18. However, the bends 26 do not oppose an outflow of a low viscosity fluid from the hollow space 18.

[0057] The bends 26 can have any desired angles and/or radii of curvature. Any desired number of bends 26 can also be provided as shown by way of example with reference to the embodiment shown in FIGS. 7 and 8. The geometric design of the channels 24 and/or their number can be adapted to the properties of the fluids used in the manufacturing process such that the desired fluids can pass through the channels 24 while other fluids are reliably prevented from doing so. Parameters that define the geometric design of the channels 24 include, among others, their length, their course, their cross-sectional shape (that can also vary in the course of the channels), and their spatial arrangement.

[0058] FIGS. 9 and 10 show comparatively short channels 24 having a cross-section that deviates from a semicircular shape. Their cross-sectional shape is approximately horseshoe-shaped here.

[0059] To create a viscosity-dependent permeability of the channels 24, the channels 24 can additionally or alternatively also have cross-sectional variations if required. A local constriction 30 is shown by way of example in FIG. 11 and is caused by an indentation of the channel wall (lower half) or a thickening of the channel wall (upper half).

[0060] In the region of the openings 28 of the channel 24 shown in FIG. 11, a connection section 32 is provided that enables the fastening of an external fluid system (not shown) to the channel 24 to be able to introduce flushing fluid into said channel 24 and/or to be able to extract flushing fluid from it. A bead (upper half) and a groove (lower half) are shown by way of example. Other fixing means, additionally or alternatively also in the interior of the channel 24, can be provided as required. A type of “insertion funnel” can also be provided in the section 32 that receives a connection element at the fluid system side.

[0061] FIGS. 12 to 14 show a base element 17A that is provided with a plurality of openings 34 at its surface to be printed. Furthermore, an opening 34A is provided at the peripheral surface of the base element 17A. As indicated by dashed lines in FIG. 14, the openings 34, 34A communicate with one another through channels 24A. If a cylinder 16 having a hollow space 18 is now printed on the surface of the element 17A, at least one connection between the hollow space 18 and the environment automatically results on a suitable distribution of the openings 34, namely at least via the opening 34A and/or another opening 34. Openings 34 not required for the respective specific case can be closed by suitable elements, e.g. plugs or stoppers. The bore pattern and/or channel pattern can be adapted as desired. The base element 17A offers great flexibility since it can be used in the manufacture of the most varied components. A base element that implements the concept explained by way of example with reference to the base element 17A can be combined with printed channels 24 and/or separate channel components.

[0062] A variant of a separate channel component is shown with reference to FIGS. 15 to 17. A separate channel component 24B is of a substantially tubular design in the example shown (see FIG. 16). The ends of the component 24B not in connection with the hollow space 18 of the cylinder 16 each have a recess 36 at their upper side, said recesses 36 enlarging the inlet opening 28. This measure can be advantageous when using comparatively high viscosity fluids. As can be seen in FIG. 17 (view from below), the component 24B extends through the cylinder 16. It thereby gives the cylinder 16 additional stability. However, in order to disturb the outflow of fluid from the hollow space 18 as little as possible, the component 24B is provided with recesses 36A at its upper side and its lower side. In addition, sidewall sections 38 of the component 24B that are located in the interior of cylinder 16 have openings 40. The recesses 36A and the openings 40A facilitate the penetration of fluids into the interior of the component 24B without unduly reducing its stabilizing effect. The component 24B can as already mentioned be a separate component that consists of the same material as the component/model to be manufactured. It can in particular be printed separately. It is, however, also possible to use a different material. In accordance with an alternative embodiment of the invention, the component 24B is printed together with the component/model to be manufactured.

[0063] The hollow space 18 can additionally or alternatively comprise (further) stabilizing or supporting elements to ensure that the cylinder 16 maintains its shape beyond the manufacturing process. Such elements can, for example, be ribs or webs that are arranged at the inner wall of the hollow space 18 and/or extend through it. Optionally, guide elements can also be provided that guide the fluids in the interior of the hollow space 18 such that the latter can be efficiently flushed and/or dried. The guide elements can simultaneously also have a stabilizing or supporting effect. The same analogously applies to the stabilizing and supporting elements.

[0064] The concept of the invention has been described above by way of example with reference to the hollow space 18 in the interior of a hollow cylinder 16. However, it is understood that this concept can generally be applied to hollow spaces or components/models of any desired shape. A hollow space in the sense of the present disclosure does not necessarily have to be a closed space. It can also be partly open and/or can be formed by an undercut.

[0065] FIGS. 18 to 20 show a system 42 in accordance with the invention that comprises a flushing apparatus 43 having a flushing chamber 43A. The model 10 still arranged on the base element 17, 17A or not is introduced into the chamber 43A.

[0066] This system is preferably combined with an apparatus for printing a component in a liquid bath.

[0067] FIG. 18 schematically shows that the openings 28 of the channels 24 (not shown) are connected to fluid system connections 44A, 44B of a fluid system in a first step to be able to flush the hollow space 18 of the model 10. This step can take place manually, semi-automatically, or automatically. This also applies to the steps described in the following. A control device is in particular provided that controls the system and suggests suitable control programs to the operator or even (partly) creates them, e.g. on the basis of external data, input data, or data determined by means of sensors. These data can, for example, be based on the digital model of the component to be produced.

[0068] The base element 17, 17A is preferably mechanically coded and/or marked to be able to always fix it in a fixedly defined position in the chamber 43A. This facilitates the automation of the process.

[0069] Flushing fluid (in particular saturated alcohol vapor) is introduced from a flushing fluid reservoir 46A into the hollow space 18 through the connection 44A. The connection 44B serves to remove the flushing fluid that is guided into a flushing fluid reservoir 468. The flushing medium can then be disposed of or recycled. Flushing or cleaning devices can additionally be provided by which the exterior of the model 10 can be flushed or cleaned. Corresponding flushing medium nozzles are in particular provided, but are not shown.

[0070] The flushing fluid can be any desired suitable liquid and/or any desired suitable gas/gas mixture.

[0071] The fluid system can also be used for drying by guiding a dry and, if necessary, heated gas/gas mixture through the hollow space 18. The flushing process and/or the drying process can each comprise a plurality of flushing or drying steps.

[0072] In the present embodiment, the flushing apparatus 43 also has a hardening apparatus 48 (for example, UV radiators) by which the model can be hardened after the flushing and/or drying. The flushing apparatus 43 thus combines the functionality of a flushing apparatus, a drying apparatus, and a hardening apparatus. It is generally also possible to implement these functionalities with separate units.

REFERENCE NUMERAL LIST

[0073] 10 model [0074] 12 dental prosthesis component [0075] 14 web [0076] 16 hollow cylinder [0077] 17, 17A base element [0078] 18 hollow space [0079] 20 embedding medium [0080] 22 housing cylinder [0081] 24, 24A, 24B channel [0082] 26 bend [0083] 28 opening [0084] 30 constriction [0085] 32 connection section [0086] 34, 34A opening [0087] 36 recess [0088] 38 side wall section [0089] 40 opening [0090] 42 system [0091] 43 flushing apparatus [0092] 43A flushing chamber [0093] 44A, 44B fluid system connection [0094] 46A, 46B flushing medium reservoir [0095] 48 hardening apparatus