Molded object, method for manufacturing molded object, optical molding device, method for creating processing program, creation program, processing program, and recording medium

Abstract

To reduce a burden on a worker.SOLUTION: A molded object formed from a cured product of a photocurable resin composition includes: a molding surface; and a support removal mark recessed against the molding surface. A surface roughness of the support removal mark is rougher than the surface roughness of the molding surface.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a technology for forming a shaped object from a cured product of a photocurable resin composition. [Background technology]

[0002] Stereolithography using a liquid photocurable resin composition is known as a method for producing shaped objects such as parts in small lots with a wide variety of varieties. While stereolithography has the advantage of being able to produce shaped objects in a short time, it requires the addition of support structures called supports to the shaped object. The supports serve to support the shaped object during stereolithography, but are unnecessary for the shaped object and must be removed after stereolithography. When removing the supports from the shaped object, it is necessary to avoid causing any significant damage to the shaped object.

[0003] Patent Document 1 discloses that, in order to prevent damage to the shaped object when the support is removed, the strength of the joint between the surface of the shaped object and the support is weakened to make it more likely to break.

[0004] Furthermore, Patent Document 2 discloses a configuration in which support marks are formed in recesses so that convex portions that become support marks after support removal do not interfere with other members. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-85837 [Patent Document 2] Japanese Patent Application Publication No. 2018-183968 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, the remaining support parts remain as protrusions on the molded object, which requires work such as polishing to remove the remaining support parts, which places a heavy burden on the worker. Furthermore, in Patent Document 2, the shape of the molded object needs to be designed to perform its required function, such as by providing recesses in the molded object so that the remaining support parts, which remain as protrusions, do not interfere with other components. This places a heavy burden on the workers involved in the design.

[0007] An object of the present invention is to reduce the burden on workers. [Means for solving the problem]

[0008] The object of the present invention is an object formed from a cured product of a photocurable resin composition, and is characterized in that it has a modeling surface and support removal marks that are recessed relative to the modeling surface, and the surface roughness of the support removal marks is coarser than the surface roughness of the modeling surface.

[0009] The method for manufacturing a molded object of the present invention is a method for manufacturing a molded object by curing a photocurable resin composition to form a molded object, and includes the steps of: irradiating the photocurable resin composition with light to form a first cured layer that becomes part of a support; and irradiating the photocurable resin composition with light to form a second cured layer that includes a first portion that overlaps the first cured layer when viewed in the thickness direction of the first cured layer, and a second portion that is located around the first portion and becomes part of the molded object.The method is characterized in that, in the step of forming the second cured layer, the second cured layer is formed so that the degree of curing of the first portion is lower than the degree of curing of the second portion.

[0010] The optical molding apparatus of the present invention is an optical molding apparatus that hardens a photocurable resin composition to form a molded object, and includes a container that stores the photocurable resin composition and a control unit that controls the light irradiated to the photocurable resin composition in the container. The control unit is capable of performing the following processes: irradiating the photocurable resin composition in the container with light to form a first cured layer that will become part of a support; and irradiating the photocurable resin composition in the container with light to form a second cured layer that includes a first portion that overlaps the first cured layer when viewed in the thickness direction of the first cured layer, and a second portion that is located around the first portion and will become part of the molded object. The control unit is characterized in that, in the process of forming the second cured layer, the irradiation energy density of the light irradiated to the second portion is controlled to be lower than the irradiation energy density of the light irradiated to the first portion.

[0011] The method for creating a processing program of the present invention is a method for creating a processing program used in optical fabrication of a model, and is characterized in that it comprises the steps of: acquiring first shape data indicating a model shape; acquiring second shape data indicating a support shape; defining a relationship between the first shape data and the second shape data so that a portion of the support shape overlaps with a first portion of the model shape; and defining the first irradiation energy density and the second irradiation energy density so that a first irradiation energy density of light used to form the first portion is lower than a second irradiation energy density of light used to form a second portion of the model shape other than the first portion.

[0012] The processing program of the present invention is a processing program to be executed by a computer of a photo-polymerization device that hardens a photo-curable resin composition to form a model, and includes the steps of causing the computer to control light irradiated to the photo-curable resin composition to form a first cured layer that will become part of a support, and causing the computer to control light irradiated to the photo-curable resin composition to form a second cured layer that includes a first portion that overlaps with the first cured layer when viewed in the thickness direction of the first cured layer, and a second portion that is located around the first portion and will become part of the model, characterized in that in the step of forming the second cured layer, the computer is caused to form the second cured layer so that the degree of hardening of the first portion is lower than the degree of hardening of the second portion. [Effects of the Invention]

[0013] According to the present invention, the burden on the worker is reduced. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of a photo-fabrication apparatus according to an embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view of a shaped object according to an embodiment. [Figure 3] 1A is a block diagram showing the configuration of a control system of a photo-fabrication apparatus according to an embodiment, and FIG. 1B is a block diagram showing the configuration of a host device according to an embodiment. [Figure 4] 3 is a flowchart showing a method for creating a machining program according to the embodiment. [Figure 5] 5(a) to 5(d) are explanatory diagrams of a method for creating a machining program according to an embodiment. [Figure 6] 1(a) to 1(i) are explanatory diagrams of a method for manufacturing a shaped object according to an embodiment. [Figure 7] FIG. 10 is a schematic cross-sectional view showing an enlarged view of a support removal mark and its surroundings on the object according to the embodiment. [Figure 8] FIG. 10 is a diagram showing experimental results of an example and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a stereolithography apparatus 100 according to an embodiment. The stereolithography apparatus 100 is an apparatus for forming a model 21 by stereolithography, i.e., an apparatus for forming the model 21 by stacking multiple cured layers obtained by curing a photocurable resin composition 1. The model 21 is a cured product of the photocurable resin composition 1. The stereolithography apparatus 100 includes a container 2, a modeling stage 3, an elevator device 4, a light irradiation unit (exposure unit) 5, and a supply device 7.

[0016] A photocurable resin composition 1 is stored in the container 2. The photocurable resin composition 1 stored in the container 2 is an uncured liquid photocurable resin composition. The photocurable resin composition 1 is, for example, an ultraviolet-curable resin composition. The photocurable resin composition 1 is, for example, radically polymerizable. As the radically polymerizable photocurable resin composition, for example, an acrylate-based resin composition can be selected. In particular, the acrylate-based resin can be selected from oligomers such as urethane acrylate-based, epoxy acrylate-based, polyester acrylate-based, and acrylic acrylate-based. The photocurable resin composition 1 may contain a reinforcing agent, such as an inorganic filler, to improve mechanical strength.

[0017] The light irradiation unit 5 is configured to irradiate the modeling stage 3 with light for curing the photocurable resin composition 1 from above the container 2, that is, to expose the modeling stage 3 to light.

[0018] The modeling stage 3 functions as a base that supports a cured product formed by curing the photocurable resin composition 1 through light irradiation by the light irradiation unit 5, and is disposed within the container 2 so as to be movable in the vertical direction (Z direction). The modeling stage 3 is driven in the Z direction by an elevator device 4. The elevator device 4 raises and lowers the modeling stage 3 in the Z direction according to input commands.

[0019] The supply device 7 is a device that supplies the photocurable resin composition 1 stored in the container 2 onto the cured product on the modeling stage 3. The supply device 7 includes a recoater or squeegee that is used to level the liquid surface 11.

[0020] The light irradiation unit 5 includes a light source 8, a mirror unit 9, and a lens unit 10. The light source 8 is, for example, a laser light source that emits laser light. The wavelength of the light emitted by the light source 8 may be any wavelength suitable for the polymerization reaction of the photocurable resin composition. For example, if the photocurable resin composition 1 is ultraviolet-curable, the light emitted is ultraviolet light, selected from a range of, for example, about 200 nm to 400 nm. The wavelength of the light emitted by the light source 8 is typically 405 nm or 365 nm.

[0021] The mirror unit 9 is configured to include a galvanometer mirror and the like. Light emitted from the light source 8 passes through the mirror unit 9 and the lens unit 10 and becomes a light spot on the liquid surface 11 of the photocurable resin composition 1 in the container 2. By driving the mirror unit 9, the light spot is scanned in the horizontal XY direction on the liquid surface 11. By such planar scanning of the light spot, it is possible to harden a portion of the photocurable resin composition 1 in the container 2 that corresponds to the shape of one layer of the model 21. Then, by lowering the modeling stage 3 by one layer at a time, it is possible to form multiple cured layers.

[0022] In the embodiment, the light irradiation unit 5 is configured to perform planar scanning of the light spot, but the present invention is not limited to this. The light irradiation unit 5 may be configured as a projector that projects image light onto the liquid surface 11.

[0023] FIG. 2 is a schematic cross-sectional view of a molded object 21 according to an embodiment. FIG. 2 illustrates the molded object 21 before and after the supports 23 are removed. The molded object 21 has support removal marks 22 formed by removing the supports 23. According to the present invention, the support removal marks 22 are recessed relative to the surrounding area of ​​the molded surface 210, preventing interference with other components. The molded surface 210 is preferably flat, but is not limited to this. A mixed layer 24 of the molded object 21 and the supports 23 before the supports 23 are removed from the molded object 21 is a portion that will become part of the molded object 21 and part of the supports 23 when the supports 23 are removed from the molded object 21. The mixed layer 24 is designed so that no convex residue remains on the molded object 21 when the supports 23 are removed from the molded object 21. Therefore, the surface condition of the support removal marks 22 in this embodiment is different from a defect. The state of the support removal marks 22 in this embodiment will be described in detail later.

[0024] 3(a) is a block diagram showing the configuration of a control system of the optical shaping apparatus 100 according to the embodiment. The optical shaping apparatus 100 includes a host device 610, a control device 620, a light irradiation control unit 605, and a stage control unit 606. The host device 610 and the control device 620 are each configured by a computer.

[0025] The host device 610 generates a processing program 630. The control device 620 acquires the processing program 630 from the host device 610, and sends control commands to the light irradiation control unit 605 and the stage control unit 606 at a predetermined control period in accordance with the processing program 630.

[0026] The light irradiation control unit 605 controls the light source 8 and mirror unit 9 of the light irradiation unit 5 in accordance with control commands received from the control device 620. The stage control unit 606 controls the elevator device 4, which drives the modeling stage 3, in accordance with control commands received from the control device 620. The stage control unit 606 also controls the supply device 7 in accordance with control commands received from the control device 620. As a result, the control device 620 controls the behavior of the light irradiation unit 5, the modeling stage 3, and the supply device 7 in accordance with the processing program 630, and can optically fabricate the model 21 on the modeling stage 3. The processing program 630 and a method for creating the processing program 630 will be described later.

[0027] The control device 620 includes a CPU 601, which is an example of a processor, a ROM 602 and a RAM 603, which are examples of storage devices, IFs 604 and 608, which are input / output interfaces, and a network interface (NIF) 609. The CPU 601, the ROM 602, the RAM 603, the IFs 604 and 608, and the NIF 609 are connected to each other so that they can communicate data with each other.

[0028] The CPU 601 acquires a machining program 630 from the host device 610 via the IF 608. The CPU 601 executes application software (control program) 635 to function as a control unit that executes a molding control procedure in accordance with the machining program 630. That is, the CPU 601 controls the light source 8 and the mirror unit 9 via the IF 604 and the light irradiation control unit 605 in accordance with the machining program 630. The CPU 601 also controls the lifting device 4 and the supply device 7 via the IF 604 and the stage control unit 606 in accordance with the machining program 630.

[0029] The ROM 602 stores a control program 635 that can be executed by the CPU 601. That is, the ROM 602 constitutes a computer-readable non-transitory recording medium that stores the control program 635. The ROM 602 may be a rewritable storage device such as an EPROM or an EEPROM. The control device 620 may also include storage such as an HDD or SSD that can store the control program 635.

[0030] The control program 635 executed by the CPU 601 is not limited to being stored in a computer-internal storage medium such as the ROM 602. The control program 635 may be stored in a storage device or a recording disk that can be supplied to the computer, as long as it is a computer-readable non-transitory storage medium. The control program 635 may also be downloaded to the computer from a network via the NIF 609.

[0031] The IFs 604 and 608 and the NIF 609 can be configured based on, for example, a serial interface standard or a parallel interface standard.

[0032] 3(b) is a block diagram showing the configuration of a host device 610 according to an embodiment. The host device 610 includes a CPU 611, which is an example of a processor, a ROM 612 and a RAM 613, which are examples of storage devices, an IF 614, which is an input / output interface, and an NIF 619, which is a network interface. The CPU 611, ROM 612, RAM 613, IF 614, and NIF 619 are connected to each other so as to be able to communicate data with each other.

[0033] The CPU 611 functions as a processing unit that creates a machining program 630 by executing application software (creation program) 640 recorded (stored) in the ROM 612. The CPU 611 creates the machining program 630 and transmits the created machining program 630 to the control device 620 via the IF 614.

[0034] The ROM 612 stores a creation program 640 executable by the CPU 611. That is, the ROM 612 constitutes a computer-readable non-transitory recording medium storing the creation program 640. The ROM 612 may be a rewritable storage device such as an EPROM or EEPROM. The host device 610 may also include storage such as an HDD or SSD capable of storing the creation program 640.

[0035] The creation program 640 executed by the CPU 611 is not limited to being stored in a computer-internal storage medium such as the ROM 612. The creation program 640 may be stored in a storage device or a recording disk that can be supplied to the computer, as long as it is a computer-readable non-transitory storage medium. The creation program 640 may also be downloaded to the computer from a network via the NIF 619.

[0036] The IF 614 and the NIF 619 can be configured based on, for example, a serial interface standard or a parallel interface standard.

[0037] The processing program 630 may be stored in a computer-readable non-transitory recording medium, such as a storage device or recording disk that can be supplied to a computer.

[0038] Next, a method for creating the machining program 630 by the host device 610 will be described. Fig. 4 is a flowchart showing a method for creating the machining program 630 according to an embodiment. Figs. 5(a) to 5(d) are explanatory diagrams of the method for creating the machining program 630.

[0039] In step S110, the CPU 611 of the host device 610 acquires object shape data 30 that indicates the object shape 40, as shown in FIG. 5(a). The object shape data 30 is an example of first shape data. The object shape data 30 is shape data created, for example, by 3D-CAD. The object shape data 30 is shape data corresponding to the object (model) desired by the user. However, since the actual object 21 has support removal marks 22 formed thereon, the shape of the object 21 is slightly different from the shape of the object 21 that is actually obtained. In other words, the object shape data 30 is shape data of an object without support removal marks. The object shape data 30 may be created in the host device 610, or may be read from an external device into the host device 610.

[0040] Furthermore, in step S120, the CPU 611 acquires multiple pieces of support shape data 31 indicating support shapes 41, as shown in FIG. 5(b). The support shape data 31 is an example of second shape data. Note that FIG. 4(b) illustrates one piece of support shape data 31. The support shape data 31 is shape data corresponding to a support, but since a portion of the support shape data 31 is inserted (engaged) into the object shape data 30 as described below, the shape of the support 23 actually obtained is slightly different. The support shape data 31 may be created in the host device 610, or may be read from an external device into the host device 610.

[0041] Taking the case of creating support shape data 31 in the host device 610 as an example, the CPU 611 determines a support arrangement surface 401 on which supports are arranged based on the object height and other factors for the object shape 40 defined by the object shape data 30 acquired in step S110. The CPU 611 then determines the support spacing based on the maximum area that can support the object with the supports, and creates multiple pieces of support shape data 31 shown in FIG. 4(b).

[0042] In step S130, the CPU 611 defines a relationship, for example, a coordinate relationship, between the object shape data 30 and the support shape data 31 so that a portion of the support shape 41 defined by the support shape data 31 overlaps with a portion 402 of the inner portion of the object shape 40 defined by the object shape data 30. As a result, the inner portion of the object shape 40 is defined as a portion 402 that overlaps with a portion of the support shape 41 and a portion 403 other than the portion 402 that does not overlap with the portion of the support shape 41. The portion 402 is an example of a first portion. The portion 403 is an example of a second portion. For example, the CPU 611 defines the coordinate relationship between the object shape data 30 and the support shape data 31 so that the support shape 41 defined by the support shape data 31 intrudes into the support placement surface 401 of the object shape 40 defined by the object shape data 30 by a predetermined amount, for example, an intrusion amount of 0.2 mm or less.

[0043] Next, in step S140, the CPU 611 slices the object shape data 30 (object shape 40) acquired in step S110 at a pitch of a predetermined thickness Δt, as shown in FIG. 5(c). As a result, the CPU 611 creates layer images 32 for multiple layers, which indicate layer data, as shown in FIG. 5(d). In the example of FIG. 5(d), layer images 32 for six layers are obtained. Of the six layer images 32, the first to sixth layers are used for modeling in order. The layer images 32 for the first and second layers are layer images without the outline of the object shape 40. The layer images 32 for the third to sixth layers are layer images including the outline of the object shape 40. The part inside the outline of the object shape 40 corresponds to the resin.

[0044] In step S140, the CPU 611 slices the support shape data 31 (support shape 41) acquired in step S120 at a pitch of a predetermined thickness Δt, as shown in FIG. 5(c), in the same coordinate system as the object shape data 30. As a result, the CPU 611 creates layer images 33 for multiple layers, which indicate the layer data, as shown in FIG. 5(d). In the example of FIG. 5(d), layer images 33 for six layers are obtained. Of the six layer images 33, the first to sixth layers are used in order for modeling. Note that the layer images 33 for the fifth and sixth layers are layer images without the outline of the support shape 41. The layer images 33 for the first to fourth layers are layer images including the outline of the support shape 41. The inside of the outline of the support shape 41 corresponds to the resin. Note that Δt corresponds to the thickness of one cured layer of the photocurable resin composition 1 formed in the modeling process.

[0045] Steps S150 to S190 are steps for processing, layer by layer, the layer images 32 and layer images 33 for the plurality of layers created in step S140. First, in step S150, the CPU 611 sets n=1.

[0046] Next, in step S160, the CPU 611 determines whether or not there are n-th layer images 32 and 33. In this case, since n=1, the CPU 611 determines whether or not there are first-layer layer images 32 and 33. If there are first-layer layer images 32 and 33 (S160: YES), the CPU 611 acquires the first-layer layer image from the layer images 32 for multiple layers and the layer images 33 for multiple layers created in step S140.

[0047] If the n-th layer images 32 and 33 do not exist (S160: NO), the CPU 611 proceeds to step S200 to create the machining program 630. The machining program 630 is created in, for example, a file format.

[0048] If step S160 is YES, in step S170, the CPU 611 determines whether there is an area in the first layer layer image 32 and layer image 33 where the area R0 inside the contour of the object shape 40 and the area R1 inside the contour of the support shape 41 overlap.

[0049] In the example of FIG. 5(d), the first layer does not have an outline of the object shape 40, so there is no area where the object shape 40 and the support shape 41 overlap, and only an area R1 inside the outline of the support shape 41 exists. Therefore, the CPU 611 defines the exposure conditions for the area R1 of the first layer, i.e., the light irradiation energy density E2. That is, the light irradiation energy density E2 when forming the supports 23 in the first layer is defined. As the light irradiation energy density E2, for example, the power of the light source 8 and the light scanning speed are defined. The light irradiation energy density E2 is defined so that the degree of cure (curing reaction rate) of the photocurable resin composition 1 is 100%, that is, so that the photocurable resin composition 1 is sufficiently cured.

[0050] Next, in step S180, the CPU 611 defines the movement amount and movement speed of the modeling stage 3. Then, in step S190, the CPU 611 increments n by 1 (n=n+1), and returns to the processing of step S160.

[0051] Since the second layer also does not have the outline of the object shape 40, there is no area where the object shape 40 and the supporting shape 41 overlap, and there is only the outline of the supporting shape 41. Therefore, the CPU 611 defines the exposure condition, i.e., the light irradiation energy density E2, for the region R1 of the second layer.

[0052] In the third layer, there is an overlapping area between the region R0 inside the contour of the object shape 40 and the region R1 inside the contour of the supporting shape 41. The overlapping area is region R1. In step S170, the CPU 611 creates a difference image 34. The difference image 34 is region R2 obtained by deleting the region R1 inside the contour of the supporting shape 41 from the region R0 inside the contour of the object shape 40.

[0053] The CPU 611 defines an exposure condition, i.e., a light irradiation energy density E2, for the third layer region R2, and defines a low exposure condition, i.e., an irradiation energy density E1 lower than the light irradiation energy density E2, for the third layer region R1. The ratio of the irradiation energy density E1 to the irradiation energy density E2 (E1 / E2) is preferably 0.3 or more and 0.7 or less, and more preferably 0.4 or more and 0.6 or less. The irradiation energy density E1 is an example of a first irradiation energy density, and the irradiation energy density E2 is an example of a second irradiation energy density.

[0054] In the fourth layer, there is also an overlapping region between region R0 inside the contour of the object shape 40 and region R1 inside the contour of the supporting shape 41. The overlapping region is region R1. Therefore, in step S170, the CPU 611 defines an exposure condition, i.e., a light irradiation energy density E2, for region R2 in the fourth layer, and defines a low exposure condition, i.e., an irradiation energy density E1 lower than the light irradiation energy density E2, for region R1 in the fourth layer.

[0055] As described above, in step S170, the CPU 611 defines the irradiation energy densities E1 and E2 such that the irradiation energy density E1 of the light used to shape the portion 402 is lower than the irradiation energy density E2 of the light used to shape the portion 403.

[0056] Since the fifth layer does not have an outline of the supporting shape 41, there is no area where the object shape 40 and the supporting shape 41 overlap, and only the outline of the object shape 40 exists. Therefore, the CPU 611 defines an exposure condition, i.e., a light irradiation energy density E2, for the area R0 of the fifth layer.

[0057] Since the sixth layer does not have an outline of the supporting shape 41, there is no area where the object shape 40 and the supporting shape 41 overlap, and only the outline of the object shape 40 exists. Therefore, the CPU 611 defines an exposure condition, i.e., the light irradiation energy density E2, for the area R0 of the sixth layer.

[0058] When definitions for all layers have been completed (S160: YES), the CPU 611 creates a file that defines the layer images 32 (excluding the third and fourth layers), the layer images 33, the differential image 34, the exposure conditions, and the operation of the modeling stage 3 as a machining program 630. The machining program 630 is sent to the control device 620 and is used to model the model 21.

[0059] A manufacturing method for manufacturing a model 21 by curing a photocurable resin composition 1 using the optical molding apparatus 100 will be described below. The CPU 601 of the control device 620 executes a molding control procedure in accordance with a processing program 630. The following describes an example in which first to sixth cured layers are formed in accordance with the processing program 630.

[0060] 6(a) to 6(i) are explanatory views of the steps of the method for producing a model 21 according to the embodiment. The model 21 is formed by curing the photocurable resin composition 1 through the following steps.

[0061] First, the container 2 shown in FIG. 1 is filled with uncured photocurable resin composition 1, and the position of the modeling stage 3 in the Z direction is adjusted so that the distance between the modeling stage 3 and the liquid level 11 is a thickness Δt. Each time the modeling stage 3 is lowered, the supply device 7 levels the liquid level 11 so that the liquid level 11 is stable. When using a photocurable resin composition 1 that shrinks when cured, it is recommended that the distance between the modeling stage 3 and the liquid level 11 be set to a value obtained by adding the amount of shrinkage to the Δt of the slice data.

[0062] In step S301 shown in Figure 6(a), the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L having an irradiation energy density E2, thereby forming a first cured layer A1 which becomes a portion 221 of the support 23.

[0063] 6(b), the CPU 601 controls the modeling stage 3 to lower the modeling stage 3 by an amount corresponding to the thickness Δt. The CPU 601 then controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L having an irradiation energy density E2, thereby forming a second cured layer A2 on the cured layer A1, which will become a portion 222 of the support 23. The cured layer A2 is an example of a first cured layer.

[0064] 6(c), the CPU 601 controls the modeling stage 3 to lower the modeling stage 3 by an amount corresponding to the thickness Δt. Then, the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L having an irradiation energy density E1, thereby forming a portion 211 on the cured layer A2 that overlaps with the cured layer A2 (portion 222) when viewed in the Z direction, which is the thickness direction of the cured layer A2.

[0065] 6(d), the light irradiation unit 5 is controlled to irradiate the photocurable resin composition 1 with light L at an irradiation energy density E2 around the portion 211, thereby forming a portion 212 that does not overlap with the cured layer A2 (portion 222) when viewed in the Z direction. That is, the portion 212 is formed after the portion 211 is formed.

[0066] In steps S303 and S304 shown in Figures 6(c) and 6(d), a third hardened layer A3 including portions 211 and 212 is formed. The hardened layer A3 is an example of a second hardened layer. The portion 212 becomes part of the object 21. The portion 212 is located around the portion 211.

[0067] In steps S303 and S304, the irradiation energy density E1 of the light irradiated when forming the portion 211 is set lower than the irradiation energy density E2 of the light irradiated when forming the portion 212, so that the degree of cure of the portion 211 is lower than the degree of cure of the portion 212. Note that the number of layers for lowering the degree of cure is not limited to one, and multiple layers may be formed consecutively.

[0068] 6(e), the CPU 601 controls the modeling stage 3 to lower the modeling stage 3 by an amount corresponding to the thickness Δt. Then, the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L having an irradiation energy density E1, thereby forming a portion 213 on the portion 211 that overlaps with the portions 211 and 222 when viewed in the Z direction.

[0069] 6(f), the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L at an irradiation energy density E2 around the portion 213, thereby forming the portion 214 that does not overlap with the portions 211 and 222 when viewed in the Z direction. That is, the portion 214 is formed after the portion 213 is formed.

[0070] 6(e) and 6(f), a fourth hardened layer A4 including the portion 213 and the portion 214 is formed. The portion 214 becomes part of the object 21. The portion 214 is located around the portion 213.

[0071] In steps S305 and S306, the irradiation energy density E1 of the light irradiated when forming portion 213 is set lower than the irradiation energy density E2 of the light irradiated when forming portion 214, so that the degree of cure of portion 213 is lower than the degree of cure of portion 214.

[0072] 6(g), the CPU 601 controls the modeling stage 3 to lower it by the thickness Δt. Then, the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L at an irradiation energy density E2, thereby forming a fifth cured layer A5, which will become a portion 215 of the model 21, on the cured layer A4.

[0073] 6(h), the CPU 601 controls the modeling stage 3 to lower it by the thickness Δt. Then, the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L at an irradiation energy density E2, thereby forming a sixth cured layer A6, which will become a portion 216 of the model 21, on the cured layer A5.

[0074] As described above, by irradiating only the necessary portions with light L emitted from the light source 8, it is possible to selectively cure the photocurable resin composition 1 on the modeling stage 3. As described above, by repeating the lowering operation of the modeling stage 3 and the irradiation of light onto the modeling stage 3 or onto the cured product on the modeling stage 3, it is possible to form a model 21 on the modeling stage 3. Note that, although an example has been described in which six cured layers A1 to A6 are formed, the number of layers in modeling the model and support is not limited to the above example.

[0075] Next, as shown in FIG. 6(i), the model 21 is removed from the stereolithography apparatus 100 and post-processed. Specifically, the modeling stage 3 to which the model 21 is fixed via the supports 23 is removed from the container 2, and the model including the model 21 and the supports 23 is separated from the modeling stage 3 using a tool such as a scraper or a spatula. Next, the uncured photocurable resin composition 1 adhering to the model 21 and the supports 23 is removed using a solvent such as ethanol or IPA. At this time, the photocurable resin composition 1 can be easily removed in a short time by using an ultrasonic cleaner.

[0076] Next, a load is applied to the supports 23 connected to the printing surface 210 of the object 21, and the supports 23 are removed from the object 21. The removal work may be performed manually by an operator, or may be performed by an operator using a tool such as a scraper.

[0077] In FIG. 6(i), the mixed layer 24 between the object 21 and the support 23 has a lower degree of hardness than the other parts, making it more susceptible to fracture during the removal of the support 23 from the object 21. This removal leaves support removal marks 22, as shown in FIG. 7, on the object 21. Note that the mixed layer 24 is embedded in the object 21 before the support 23 is removed from the object 21. Therefore, before the support 23 is removed from the object 21, the mixed layer 24 is not exposed to the outside, or only a small amount is exposed to the outside. When the support 23 is removed from the object 21, the mixed layer 24 fractures, becoming part of the object 21 and part of the support 23. FIG. 7 is a schematic enlarged cross-sectional view of the support removal marks 22 and their surroundings on the object 21. The support removal marks 22 have a concave shape that is lower than the printing surface 210 of the object 21.

[0078] The support removal marks 22 are formed in a concave shape, i.e., a bowl shape, with a smooth mean line of the roughness curve in the cross section. The depth of the support removal marks 22 is preferably 0.5 mm or less, and more preferably 0.2 mm or less. That is, the thickness of the mixed layer 24 irradiated with light having the above-mentioned irradiation energy density E1 is preferably 0.5 mm or less, and more preferably 0.2 mm or less. This effectively prevents damage to the model 21 when the supports 23 are removed from the model 21.

[0079] The surface roughness of the support removal marks 22 is higher than the surface roughness of the build surface 210. This is because the hardness of the mixed layer 24 is lower than that of the other parts, causing ductile fracture at the interface between the build object 21 and the support 23, resulting in a fracture surface that is rougher than the build surface 210 of the build object 21.

[0080] When measured with a laser microscope using a 20x lens with a resolution of 0.005 μm, the arithmetic mean roughness Ra of the modeling surface 210 of the model 21 is 5 μm. In contrast, the arithmetic mean roughness Ra of the support removal marks 22 is 10 μm or more and 15 μm or less.

[0081] The shape of the support removal marks 22 is determined by the cross-sectional shape of the supports 23, but in consideration of removability, it is preferable that the shape be circular in plan view. That is, it is preferable that the cross-sectional shape of the support removal marks 22 be bowl-shaped.

[0082] Considering the strength of the support 23, the diameter of the support removal mark 22 in plan view is preferably 0.3 mm or more and 1.0 mm or less.

[0083] As described above, according to this embodiment, since the support removal marks 22 are concave when the supports 23 are removed, it is possible to reduce the labor required for smoothing the support removal marks, which would otherwise be convex, and the burden on the worker is thereby reduced. This improves work efficiency and reduces the manufacturing cost of the shaped object 21.

[0084] [Example] Examples 1 and 2 will be described. A modeling experiment was carried out using the optical modeling apparatus 100 shown in Fig. 1 in an environment of approximately 25°C to produce a model 21 having a width of 50 mm, a depth of 30 mm, and a height of 10 mm. The illumination light had a wavelength of 405 nm and a maximum illuminance of 10 mW / cm. 2 The size of the container 2 was approximately 70 mm x 50 mm x 30 mm. The photocurable resin composition 1 was cured by irradiating it with light using a DMD element with a resolution of 1920 pixels x 1080 pixels. The size of the modeling stage 3 was 60 mm x 50 mm. The photocurable resin composition 1 was a mixture of epoxy and acrylic with inorganic filler added.

[0085] The shaping conditions are as follows: the irradiation energy density E2 of the shaping object 21 and the support 23 is 80 mJ / cm 2 The irradiation energy density E1 of the mixed layer 24 of the object 21 and the support 23 was set to 30 mJ / cm 2 (Example 1) and 50 mJ / cm 2 After the shaping process was completed, the worker removed the supports 23 by hand.

[0086] After the support 23 was removed, the molded object 21 was washed with ethanol to remove excess resin liquid adhering to the molded object 21, and then dried in a draft chamber for 20 minutes, and the size of the support removal marks 22 was evaluated using a laser microscope.

[0087] As a comparative example, there is no mixed layer of the object and the support, and the irradiation energy density E2 of the object and the support is 80 mJ / cm 2 In the comparative example, similarly to Examples 1 and 2, the marks left by support removal were evaluated.

[0088] The evaluation results are shown in Figure 8. The evaluation results were as follows: A: The marks left by removing the support are concave relative to the surface of the object; B: The marks left by removing the support are convex relative to the surface of the object.

[0089] According to FIG. 8, in the comparative example, the support removal marks were convex on the modeling surface of the model, and the size of the convex shapes was 150 μm to 250 μm.

[0090] In Examples 1 and 2, the mixed layer 24 was irradiated with 30 mJ / cm 2 More than 50mJ / cm 2 When formed at the following irradiation energy density E1, the object 21 could be manufactured without any molding defects, and the support removal marks 22 were concave relative to the molding surface 210 of the object 21. In this case, the ratio of the irradiation energy density E1 to the irradiation energy density E2 (E1 / E2) was 0.375 or more and 0.625 or less. It was confirmed that the size of the support removal marks 22 was a maximum of 190 μm.

[0091] The degree of hardening (curing reaction rate) of the portion of the object 21 where the modeling surface 210 was formed and the degree of hardening (curing reaction rate) of the portion of the object 21 where the support removal marks 22 were formed were measured by FT-IR. As a result, in Examples 1 and 2, the ratio of the degree of hardening (curing reaction rate) of the portion of the object 21 where the modeling surface 210 was formed to the degree of hardening of the portion of the object 21 where the support removal marks 22 were formed was 0.4 to 0.8. In percentage terms, this ratio was 40% to 80%. That is, according to Examples 1 and 2, by setting the above ratio, the concave support removal marks 22 can be formed to a depth that does not impair the external shape (aesthetics) of the object 21, i.e., 0.5 mm or less, preferably 0.2 mm or less. In particular, considering the function of the supports 23, it is preferable that the support removal marks 22 be formed to a depth of 80 μm to 190 μm.

[0092] The present invention is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present invention. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments.

[0093] (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0094] In the above embodiment, the host device 610 and the control device 620 are configured as separate computers, but the present invention is not limited to this and may be configured as a single computer. In this case, the machining program 630 can be created and executed by the single computer.

[0095] The disclosure of the above embodiments includes the following configurations and methods.

[0096] (Configuration 1) A shaped object formed from a cured product of a photocurable resin composition, A support removal mark is formed on the surface of the mold, and the support removal mark is recessed relative to the surface of the mold, The surface roughness of the support removal marks is greater than the surface roughness of the build surface. A sculpted object characterized by the above.

[0097] (Configuration 2) The arithmetic mean roughness Ra of the support removal marks is 10 μm or more and 15 μm or less. The object according to configuration 1, characterized in that:

[0098] (Configuration 3) The depth of the support removal marks is 0.5 mm or less. 3. The shaped object according to configuration 1 or 2.

[0099] (Configuration 4) The depth of the support removal marks is 0.2 mm or less. 4. The shaped object according to any one of configurations 1 to 3.

[0100] (Configuration 5) The support removal mark is bowl-shaped. 5. The shaped object according to any one of configurations 1 to 4.

[0101] (Configuration 6) The diameter of the support removal mark is 0.3 mm or more and 1.0 mm or less. 6. The object according to configuration 5,

[0102] (Configuration 7) a ratio of the hardness of the portion of the object where the support removal marks are formed to the hardness of the portion of the object where the modeling surface is formed is 0.4 or more and 0.8 or less; 7. The shaped object according to any one of configurations 1 to 6,

[0103] (Method 8) A method for manufacturing a shaped object by curing a photocurable resin composition to form a shaped object, comprising the steps of: irradiating the photocurable resin composition with light to form a first cured layer that will become part of the support; irradiating a photocurable resin composition with light to form a second cured layer including a first portion overlapping the first cured layer when viewed in the thickness direction of the first cured layer, and a second portion positioned around the first portion and becoming part of the shaped object; In the step of forming the second hardened layer, the second hardened layer is formed so that the degree of hardness of the first portion is lower than the degree of hardness of the second portion. A method for manufacturing a shaped object, comprising:

[0104] (Method 9) In the step of forming the second hardened layer, a first irradiation energy density of the light irradiated to the first portion is lower than a second irradiation energy density of the light irradiated to the second portion. 9. The method for producing a shaped object according to method 8,

[0105] (Method 10) a ratio of the first irradiation energy density to the second irradiation energy density is 0.3 or more and 0.7 or less; 10. The method for producing a shaped object according to method 9,

[0106] (Method 11) further comprising removing the support from the object; By the support removing step, support removal marks that are recessed relative to the modeling surface of the model are formed on the model. 11. The method for producing a shaped object according to any one of Methods 8 to 10,

[0107] (Configuration 12) A stereolithography apparatus for curing a photocurable resin composition to form a shaped object, comprising: a container for storing a photocurable resin composition; a control unit that controls the light irradiated onto the photocurable resin composition in the container, The control unit a process of irradiating the photocurable resin composition in the container with light to form a first cured layer that will become a part of the support; and irradiating the photocurable resin composition in the container with light to form a second cured layer including a first portion overlapping the first cured layer when viewed in the thickness direction of the first cured layer, and a second portion positioned around the first portion and becoming part of the shaped object. In the process of forming the second hardened layer, the irradiation energy density of the light irradiated to the second portion is controlled to be lower than the irradiation energy density of the light irradiated to the first portion. A photolithography apparatus characterized by:

[0108] (Method 13) A method for creating a processing program used in stereolithography of a shaped object, comprising: acquiring first shape data indicating a shape of an object; obtaining second shape data indicative of a support shape; defining a relationship between the first shape data and the second shape data such that a portion of the support shape overlaps a first portion of the object shape; defining the first irradiation energy density and the second irradiation energy density so that a first irradiation energy density of light used to model the first portion is lower than a second irradiation energy density of light used to model a second portion other than the first portion in the shape of the object; A method for creating a machining program.

[0109] (Configuration 14) A creating program for causing a computer to execute the machining program creating method according to Method 13.

[0110] (Configuration 15) A processing program to be executed by a computer of a stereolithography device that forms a shaped object by curing a photocurable resin composition, causing the computer to control light irradiated onto the photocurable resin composition to form a first cured layer that becomes a part of the support; and causing the computer to control light irradiated onto the photocurable resin composition to form a second cured layer including a first portion overlapping the first cured layer when viewed in a thickness direction of the first cured layer, and a second portion positioned around the first portion and becoming a part of the shaped object, In the step of forming the second hardened layer, the computer is caused to form the second hardened layer such that a degree of hardness of the first portion is lower than a degree of hardness of the second portion. A machining program characterized by:

[0111] (Configuration 16) A computer-readable recording medium having the creation program according to configuration 14 recorded thereon.

[0112] (Configuration 17) A computer-readable recording medium having the machining program according to configuration 15 recorded thereon. [Explanation of symbols]

[0113] 1...photocurable resin composition, 21...modeled object, 22...support removal marks, 23...support, 100...stereolithography device, 630...processing program, 640...creation program

Claims

1. A shaped object formed from a cured product of a photocurable resin composition, A support removal mark is formed on the support surface. The surface roughness of the support removal marks is greater than the surface roughness of the modeling surface; A structure characterized by the above.

2. The arithmetic average roughness Ra of the support removal mark is 10 μm or more and 15 μm or less. The object according to claim 1,

3. The depth of the support removal mark is 0.5 mm or less. The object according to claim 1 .

4. The depth of the support removal mark is 0.2 mm or less. The object according to claim 1 .

5. The support removal mark is bowl-shaped. The object according to claim 1 .

6. The diameter of the support removal mark is 0.3 mm or more and 1.0 mm or less. The object according to claim 5 .

7. a ratio of a hardness of a portion of the object where the support removal traces are formed to a hardness of a portion of the object where the modeling surface is formed is 0.4 or more and 0.8 or less. The object according to any one of claims 1 to 6.

8. A method for producing a shaped object by curing a photocurable resin composition to form a shaped object, comprising the steps of: A step of irradiating the photocurable resin composition with light to form a first cured layer that becomes a part of the support; and forming a second cured layer including a first portion overlapping the first cured layer when viewed in a thickness direction of the first cured layer, and a second portion positioned around the first portion and becoming a part of the shaped object, by irradiating a photocurable resin composition with light, In the step of forming the second hardened layer, the second hardened layer is formed so that a degree of hardening of the first portion is lower than a degree of hardening of the second portion. A method for manufacturing a shaped object comprising the steps of:

9. In the step of forming the second hardened layer, a first irradiation energy density of the light irradiated to the first portion is lower than a second irradiation energy density of the light irradiated to the second portion. The method for manufacturing a shaped object according to claim 8 .

10. a ratio of the first irradiation energy density to the second irradiation energy density is 0.3 or more and 0.7 or less; The method for manufacturing a shaped object according to claim 9 .

11. removing the support from the object; by removing the support, a support removal mark that is recessed relative to the modeling surface of the model is formed on the model. The method for manufacturing a shaped object according to any one of claims 8 to 10.

12. A photo-molding apparatus for forming a model by curing a photo-curable resin composition, comprising: A container for storing a photocurable resin composition; A control unit that controls the light irradiated to the photocurable resin composition in the container, The control unit is A process of irradiating the photocurable resin composition in the container with light to form a first cured layer that becomes a part of the support; and irradiating the photocurable resin composition in the container with light to form a second cured layer including a first portion overlapping the first cured layer when viewed in a thickness direction of the first cured layer, and a second portion positioned around the first portion and becoming a part of the object. The control unit controls, in the process of forming the second hardened layer, a first irradiation energy density of light irradiated to the first portion to be lower than a second irradiation energy density of light irradiated to the second portion. A photolithography apparatus comprising:

13. A method for creating a processing program used in optical modeling of a shaped object, comprising the steps of: acquiring first shape data indicating a shape of an object; obtaining second shape data indicative of a support shape; defining a relationship between the first shape data and the second shape data such that a portion of the support shape overlaps a first portion of the object shape; defining the first irradiation energy density and the second irradiation energy density such that a first irradiation energy density of light used for modeling the first portion is lower than a second irradiation energy density of light used for modeling a second portion other than the first portion in the shape of the object. A method for creating a machining program comprising the steps of:

14. A creating program for causing a computer to execute the machining program creating method according to claim 13.

15. A processing program to be executed by a computer of a stereolithography apparatus for forming a model by curing a photocurable resin composition, A step of causing the computer to control light irradiated to the photocurable resin composition to form a first cured layer that becomes a part of the support; and causing the computer to control light irradiated to the photocurable resin composition to form a second cured layer including a first portion overlapping the first cured layer when viewed in a thickness direction of the first cured layer, and a second portion located around the first portion and becoming a part of the object. In the step of forming the second hardened layer, the computer is caused to form the second hardened layer such that a degree of hardness of the first portion is lower than a degree of hardness of the second portion. A machining program characterized by:

16. A computer-readable recording medium having the creation program according to claim 14 recorded thereon.

17. A computer-readable recording medium having the machining program according to claim 15 recorded thereon.

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