Device and method for radiation curing, device and method for 3D printing

Abstract

The present invention relates to the field of radiation curing and 3D printing of objects to be cured by radiation. To present a solution that allows the simultaneous radiation curing of several objects, thereby avoiding or at least reducing the disadvantages of partially insufficient curing or potentially excessive irradiation, a radiation curing device is proposed comprising a curing chamber and at least one chamber separator configured to divide the curing chamber into sub-chambers, such that each sub-chamber is designed to accommodate at least one of several objects to be cured, the several objects to be cured being jointly supported by a carrier, and the curing chamber and the at least one chamber separator each comprising at least one radiation source configured for radiation curing.

Description

[0001] The present invention relates to the field of radiation curing and 3D printing of radiation-curable objects, in particular objects such as dental splints or similar items.

[0002] In the conventional way, an object to be hardened by radiation (e.g. light), which was produced by means of 3D printing, is exposed to (light) radiation in a basically simple box with a lid and thus hardened, i.e. the polymerization is completed as completely as possible.

[0003] To increase the throughput of objects to be hardened, several objects are sometimes placed together in the radiation hardening unit, with the aim of carrying out the radiation hardening for these objects in parallel rather than one after the other.

[0004] However, it has been found that such joint radiation hardening of several objects sometimes leads to mutual shading of the objects, especially in the case of larger objects (i.e., objects that are not significantly smaller compared to the radiation hardening unit or the arrangement of radiation sources), meaning that the arrangement of the several objects relative to each other results in individual objects or at least sections of them receiving less radiation, so that the hardening is then not complete.

[0005] This leads to disadvantages insofar as disruptive or even harmful (e.g., toxic) photoinitiators and / or monomers remain in the supposedly hardened object. If such an object is to be used, for example, as a dental splint, these disadvantages are unacceptable.

[0006] EP 3 815 646 A1 discloses an exposure unit in which one or more light sources are placed on the walls.

[0007] EP 2 545 882 A1 discloses an exposure unit in which several LEDs are placed on the walls. The object is located on a rotating plate. Individual small objects can be well exposed in this way. Nevertheless, there is a risk of shadowing, especially when several larger objects are exposed simultaneously.

[0008] EP 3 195 828 A1 discloses an exposure unit containing several light sources and a rotating plate.

[0009] DE 10 2005 019 386 A1 discloses an exposure unit that can detect the intrinsic radiation of the exposed dental material by means of a sensor. In one embodiment, the dental objects can also be located in individual chambers. The chambers are separated by partitions (not LED panels). The light sources are located above each individual chamber.

[0010] US 2022 / 0273409 A1 discloses a post-exposure unit that uses multiple LEDs for exposure. The LEDs are mounted on the walls and / or floor / ceiling surfaces. The light comes from different directions. If several (especially larger) objects were placed in the chamber, there would be a risk of shadows forming.

[0011] KR 10-2575220 B1 discloses a post-exposure unit in which a first light source is located above and a second light source is located below the object. The light sources can be modules consisting of several LEDs. The light sources can optionally be moved vertically towards the object. Despite the mobility of the light sources, there is still a risk of shadow formation, especially when several larger objects are exposed simultaneously.

[0012] US 2023 / 0339190 A1 discloses a post-exposure unit in which an exposure unit can be moved relative to the object. By changing the position and changing the wavelength or intensity, an object with spatially different properties can be produced through selective exposure. According to the teaching of US 2023 / 0339190 A1, an arrangement of two LED panels is used to reduce shadow formation.

[0013] EP 4 464 490 A1 discloses a post-exposure unit having at least three side walls capable of reflecting radiation. LED units are arranged at the edges between the surfaces. According to the teaching of EP 4 464 490 A1, this arrangement is intended to achieve uniform illumination throughout the entire chamber. Although the (empty) chamber may be optimally illuminated, there is a risk of shadowing in the areas between the objects, particularly when several larger objects are present.

[0014] WO 2024 / 141861 A1 discloses a post-exposure unit suitable for both cleaning and exposing the object. Excess uncured resin is deposited by rapid rotation, thus cleaning the object. The device can have one or more light sources.

[0015] WO 2023 / 076570 A1 discloses a method and a system for cleaning a 3D-printed object by means of rapid rotation. The system can optionally also be designed for post-curing.

[0016] In principle, insufficient irradiation in some areas could be addressed by extending the irradiation time for all objects. However, this has its drawbacks, as longer irradiation requires more energy (and time), and excessive irradiation of objects that have already hardened can lead to premature aging.

[0017] Similarly, the problem of mutual shading – sometimes not even recognized in the prior art – could at least be reduced by designing the irradiation unit to be so large that, in comparison, the objects to be cured are so small or so far apart that no or only negligible shading occurs. However, such an oversized design of the irradiation unit is uneconomical.

[0018] Likewise, the trivial possibility of providing a separate radiation hardening device for each of the objects is uneconomical, not least because each of the objects would then have to be handled individually.

[0019] One objective underlying the present invention is to enable radiation hardening in an economically viable manner in which several objects to be radiation-hardened are treated together, i.e. simultaneously.

[0020] It is therefore desirable to present a solution that allows simultaneous radiation hardening of several objects, avoiding or at least reducing the disadvantages of partially insufficient hardening or potentially excessive irradiation.

[0021] According to a first aspect of the invention, a device for radiation hardening is proposed as defined in claim 1, namely with a hardening chamber and at least one chamber separator configured to divide the hardening chamber into sub-chambers, such that the sub-chambers are each configured to receive at least one of several objects to be hardened, wherein the several objects to be hardened are jointly supported by a carrier, wherein the hardening chamber and the at least one chamber separator each have at least one radiation source configured for radiation hardening.

[0022] According to a second aspect of the invention, a method for radiation hardening is proposed as defined in claim 7, namely comprising arranging or producing several objects to be hardened in such a way that the several objects to be hardened are jointly supported by a carrier, providing a radiation hardening device according to the invention, inserting the several objects to be hardened, which are jointly supported by the carrier, into at least a part of the sub-chambers of the radiation hardening device, so that at least one object to be hardened is located in two or more of the sub-chambers, and irradiating the several objects to be hardened with radiation sources of the radiation hardening device.

[0023] According to a third aspect of the invention, a method for printing several radiation-cured objects is proposed, as defined in claim 8, namely by determining an arrangement of at least one chamber separator in a radiation-curing device according to the invention and by planning a 3D print of the several radiation-cured objects, wherein the planning takes into account a specific arrangement and / or the determination of a plan as a boundary condition.

[0024] By providing a support structure that can serve both as a "lid" (or more generally, wall) for the curing chamber and can also be manufactured concurrently with the objects to be cured by radiation—that is, produced together with the objects (in particular, integrally with them)—an arrangement of the objects is possible that, in turn, allows for the inclusion of a chamber separator between each object. If the chamber separator is equipped with a suitable radiation source, the resulting sub-chambers each functionally constitute a separate curing chamber, ensuring that no shadowing by another object occurs within that curing chamber.

[0025] In an advantageous embodiment of one aspect of the invention, the curing chamber and the at least one chamber separator are configured such that the at least one chamber separator can be arranged in different positions and / or orientations within the curing chamber, and / or that the at least one chamber separator can be removed from the curing chamber. The chamber separator, which, unlike a fixed wall, can be arranged in different locations and / or orientations within the curing chamber, allows the curing chamber to be divided into sub-chambers while maintaining flexibility, so that the curing chamber divided into sub-chambers is not limited to a specific arrangement or configuration of objects to be cured by radiation.

[0026] In a preferred embodiment of the above design, the hardening chamber has at least one support section, in particular a rail, for the at least one chamber separator, wherein the support section is preferably further configured for supplying power to the at least one radiation source of the chamber separator it supports. It is advantageous if a structure that, like the support section, has a load-bearing function, is also used for an additional function such as supplying power.

[0027] In another advantageous embodiment of an aspect of the invention, the curing chamber has several opposing wall sections, each equipped with at least one radiation source, and / or the at least one chamber separator has a front and a back, the front and back each being equipped with a radiation source. By arranging the radiation source on the walls surrounding the object or on the side of the chamber separator facing the object, particularly good illumination of the object can be achieved.

[0028] In another advantageous embodiment of an aspect of the invention, the curing chamber has a wall with an opening for receiving the support, so that in an operating state, the wall of the curing chamber and the support together enclose an interior space of the curing chamber in which the at least one chamber separator is received. Here, the support not only serves to hold the objects relative to one another, but also acts as the wall of the curing chamber. The support can also be equipped with one or more radiation sources.

[0029] In another advantageous embodiment of an aspect of the invention, the radiation curing device, together with a printing unit for producing multiple radiation-curable blanks, forms part of a 3D printing device. The 3D printing device is configured such that several blanks produced by the printing unit, which are jointly supported by a carrier, can be fed to the radiation curing device. Combining a 3D printing unit with the radiation curing device allows for the automation of the production of the radiation-cured objects. The 3D printing device can also be equipped with additional units that are beneficial to the overall manufacturing process, such as a cleaning unit for cleaning the printed blanks before radiation curing.Furthermore, the 3D printing device may also include a post-processing unit that, for example, separates the radiation-cured objects from the carrier and, if necessary, from each other.

[0030] In an advantageous embodiment of one aspect of the invention, a method for 3D printing comprises the inventive method for print planning and the inventive method for radiation curing.

[0031] According to a further aspect of the invention, a computer program is proposed with programming means that cause a computer to execute the steps of the method according to claim 8 when the computer program is executed on the computer. The computer program can be provided, stored, and / or distributed on a suitable storage medium, such as an optical storage medium or a non-volatile electronic storage medium. It can also be provided together with or as part of a hardware component. The computer program can also be provided in other ways, such as via the Internet or via wired or wireless telecommunications.

[0032] Features of advantageous embodiments of the invention are defined in particular in the dependent claims, with further advantageous features, embodiments and configurations also being apparent to the person skilled in the art from the above explanation and the following discussion.

[0033] The present invention will now be further illustrated and explained with reference to exemplary embodiments shown in the figures. Here, Fig. 1 A schematic representation illustrating an embodiment of a radiation hardening device, Fig. 2 a further schematic representation to illustrate the embodiment of a device for radiation hardening, Fig. 3. A further schematic representation to illustrate the embodiment of a device for radiation hardening, Fig. 4. A further schematic representation to illustrate the embodiment of a device for radiation hardening, Fig. 5 a further schematic representation to illustrate the embodiment of a device for radiation hardening, Fig. 6 a schematic representation to illustrate an embodiment of a device for 3D printing, and Fig. 7 a schematic flowchart of an embodiment of a method according to the invention.

[0034] In the accompanying drawings and the explanations relating to these drawings, corresponding or related elements are marked with corresponding or similar reference symbols, where appropriate, even if they are found in different embodiments.

[0035] Fig. Figure 1 shows a schematic representation illustrating an embodiment of a radiation hardening device 10. The device comprises a hardening chamber 12 in which three chamber separators 14 are arranged, dividing the hardening chamber 12 into four sub-chambers. This division into sub-chambers need not be hermetically sealed, as shown in the illustration of Fig. As can be seen, it is not necessary for the chamber separators 14 to be flush with or abut the wall of the curing chamber 12. The chamber separators 14 are mounted on a rail 16 running through the curing chamber 12, along which the chamber separators 14 can be arranged. The chamber separators 14 can be removed from the rail 16, and additional chamber separators 14 can be added. It is also possible, instead of removing or adding chamber separators 14, to provide a certain number of chamber separators 14 in the curing chamber, which can be arranged as needed, with unused chamber separators 14 being "parked," for example, against a wall of the curing chamber 12.

[0036] The invention is not limited to the specific design and orientation of the rail 16. Multiple rails can be provided, which can also extend in different directions. The rail(s) is / are not limited to being straight.

[0037] The Fig. 2, Fig. 3, Fig. 4 to Fig. Figure 5 shows further schematic representations to illustrate the exemplary embodiment of a device 10 for radiation hardening. While the representation of Fig. 1 from "above" looking into the device 10 shows Fig. 2. A section view perpendicular to this, i.e., a side section view.

[0038] In Fig. 2 is, as already mentioned in Fig. 1. It can be seen that the chamber separators 14 are arranged parallel to each other in the hardening chamber 12. However, the invention is not limited to a planar design of the chamber separators 14 or to a specific arrangement of the chamber separators 14 relative to each other.

[0039] In Fig. 2. Several radiation sources 18 are present on the wall of the hardening chamber 12 shown. The person skilled in the art is sufficiently familiar with the design and function of the radiation sources 18 for radiation hardening as such, so that no further explanation is necessary.

[0040] Fig. Figure 3 shows objects 20 to be hardened, which are supported side by side by a carrier 22, here a building platform for 3D printing.

[0041] Fig. Figure 4 shows the objects 20 and the support 22, which are inserted into the hardening chamber 12 and the sub-chambers, respectively. Compared to the illustration of Fig. For the sake of clarity, radiation sources 18 are not shown here.

[0042] Fig. Figure 5 shows a chamber separator 14 in a view perpendicular to both the representation from Fig. 1 as well as for representation from Fig. 2. The chamber separator 14 is equipped with radiation sources 18. The chamber separator 14 is powered by the already in Fig. 1 and Fig. 2 shown rail 16, which is also designed to supply energy to the radiation sources 18.

[0043] Fig. Figure 6 shows a schematic representation to illustrate an embodiment of a device 100 for 3D printing.

[0044] The device 100 for 3D printing comprises a printing unit 110, a washing unit 120, a radiation curing device 10 and a transport unit 130.

[0045] The pressure unit 110 is designed for the production of multiple radiation-curable blanks. Those skilled in the art are sufficiently familiar with the production of such blanks, so no further explanation is necessary.

[0046] The transport unit 130 is designed to feed the group of blanks from the printing unit 110 to the washing unit 120, which is designed for washing the blanks. Since those skilled in the art are sufficiently familiar with the washing of the blanks, no further explanation is necessary here either.

[0047] The transport unit 130 is further designed to supply the group of blanks from the washing unit 120 to the device 10 for radiation hardening, so that the blanks can be hardened there by radiation.

[0048] Fig. Figure 7 shows a schematic flowchart of an embodiment of a method according to the invention.

[0049] In step S1, an arrangement of at least one chamber separator in a radiation curing device according to the invention is determined. In step S2, a 3D print of the objects to be radiation cured is planned.

[0050] Steps S1 and S2 together form a procedure for print planning for 3D printing and are related in that at least one of the steps takes the result of the other into account as a boundary condition, whereby this consideration can also include further iterations.

[0051] In step S3, which follows the planning (not necessarily immediately), the several radiation-cured objects (as blanks) are manufactured by 3D printing, so that the objects are held together by a support.

[0052] In step S4, a radiation hardening device according to the invention is provided, into which the objects held jointly by the carrier are placed in step S5, wherein in step S4 the chamber separators of the radiation hardening device were arranged in a suitable manner so that the objects are each received in a sub-chamber.

[0053] In step S6, the objects are hardened by radiation using the appropriate radiation sources.

[0054] Even if the figures show different aspects or features of the invention in combination, it is apparent to the person skilled in the art - unless otherwise stated - that the combinations shown and discussed are not the only possible ones.

[0055] In implementations of the invention, individual components, e.g., a processor, can wholly or partially assume the functions of various elements mentioned in the claims. Processes or procedures, such as determining an arrangement or planning a 3D print, can be implemented as program elements of a computer program and / or as special hardware components. Reference symbol list 10 Device for radiation hardening 12 hardening chamber 14 chamber separator 16 rail 18 radiation source 20 objects 22 carriers 100 devices for 3D printing 110 printing units 120 washing units 130 transport units S1 Determining an arrangement S2 Planning a 3D print S3 Production of blanks S4 Provision of the radiation hardening device S5 Inserting the blanks S6 radiation hardening

Claims

[1] Device for radiation hardening, comprising: a hardening chamber and at least one chamber separator designed to divide the hardening chamber into sub-chambers, such that each sub-chamber is designed to accommodate at least one of several objects to be hardened, wherein the several objects to be hardened are jointly supported by a carrier, wherein the hardening chamber and the at least one chamber separator each have at least one radiation source designed for radiation hardening. [2] Device for radiation hardening according to claim 1, wherein the hardening chamber and the at least one chamber separator are configured such that the at least one chamber separator can be arranged in different positions and / or in different orientations within the hardening chamber, and / or that the at least one chamber separator can be removed from the hardening chamber. [3] Device for radiation hardening according to claim 2, wherein the hardening chamber has at least one support section, in particular a rail, for the at least one chamber separator, wherein the support section is preferably further configured for a power supply to the at least one radiation source of the chamber separator it supports. [4] Device for radiation hardening according to one of the preceding claims, wherein the hardening chamber has several opposing wall sections, each equipped with at least one radiation source, and / or wherein the at least one chamber separator has a front and a back, wherein the front and the back are each equipped with a radiation source. [5] Device for radiation hardening according to one of the preceding claims, wherein the hardening chamber has a wall which has an opening for receiving the carrier, so that in an operating state the wall of the hardening chamber and the carrier together enclose an interior space of the hardening chamber in which the at least one chamber separator is received. [6] Device for 3D printing, comprising a printing unit for producing multiple radiation-curable blanks, and a radiation curing device according to one of the preceding claims, wherein the 3D printing device is configured to allow multiple blanks produced by the printing unit, which are jointly supported by a carrier, to be fed to the radiation curing device. [7] Methods for radiation hardening, with: Arranging or manufacturing several objects to be hardened in such a way that the several objects to be hardened are jointly supported by a carrier, Provision of a device for radiation hardening according to one of claims 1 to 5, Inserting the several objects to be hardened, which are jointly supported by the carrier, into at least a part of the sub-chambers of the radiation hardening device, such that at least one object to be hardened is located in two or more of the sub-chambers, and Irradiation of the several objects to be hardened with radiation sources of the radiation hardening device. [8] Method for print planning for a 3D print of multiple radiation-curable objects, with: Determining an arrangement of at least one chamber separator in a radiation hardening device according to one of claims 1 to 5, and Planning a 3D print of the several radiation-cured objects, where planning takes into account a specific arrangement and / or determining a plan as a boundary condition. [9] Method for 3D printing comprising the steps of the print planning method according to claim 8 and the steps of the radiation curing method according to claim 7. [10] Computer program comprising programming means that cause a computer to perform the steps of the method according to claim 8 when the computer program is executed on the computer.

Images