Molded object, method for manufacturing molded object, stereolithography apparatus, method for creating a 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 technique for a molded object formed of a cured product of a photocurable resin composition.

Background Art

[0002] As a method for manufacturing a molded object such as parts in small lots of various types, optical modeling using a liquid photocurable resin composition is known. In optical modeling, while there is an advantage that a molded object can be produced in a short time, it is necessary to add a support structure called a support and perform modeling. The support serves to support the molded object during optical modeling, but since it is unnecessary for the molded object, it needs to be removed after optical modeling. And when removing the support from the molded object, it is necessary to prevent large defects from occurring in the molded object.

[0003] Patent Document 1 discloses that in order to make it difficult for defects to occur in the molded object when removing the support, the strength of the joint portion between the surface of the molded object and the support is weakened to make it easier to break.

[0004] Further, Patent Document 2 discloses a configuration in which a support mark is formed in a concave portion so that a convex portion that becomes a support mark after support removal does not interfere with other members.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in Patent Document 1, the remaining support structures remain as protrusions on the fabricated object, requiring work such as polishing to remove them, which places a heavy burden on the worker. Furthermore, in Patent Document 2, it is necessary to design the shape of the fabricated object so that the remaining support structures do not interfere with other components, for example by creating recesses in the fabricated object so that the support structures fit within the recesses, thereby ensuring that the shape of the fabricated object performs its intended function. This also places a heavy burden on the workers involved in the design.

[0007] The present invention aims to reduce the burden on workers. [Means for solving the problem]

[0008] The molded object of the present invention is a molded object formed from a cured product of a photocurable resin composition, and has a molded surface and support removal marks that are recessed relative to the molded surface. The molded object has a first surface, and the molded surface and the support removal marks are provided on the first surface. The surface roughness of the support removal marks is characterized by being rougher than the surface roughness of the molded surface.

[0009] The method for manufacturing the molded object of the present invention is: Stored in a container Photocurable resin composition Irradiate with light to produce a photocurable resin composition harden On the modeling stage A method for manufacturing a molded object, comprising the steps of: irradiating a photocurable resin composition with light to form a first cured layer that will be part of the support; and irradiating the photocurable resin composition with light 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 be part of the molded object, wherein in the step of forming the second cured layer, the second cured layer is formed such that the degree of curing of the first portion is lower than the degree of curing of the second portion. death , The support is formed between the molding stage and the molded object. It is characterized by the following:

[0010] The photopolymerization apparatus of the present invention is a photocurable resin composition Irradiate with light to produce a photocurable resin composition A stereolithography apparatus for curing a material to form a molded object, comprising a container for storing a photocurable resin composition, A molding stage is placed inside the aforementioned container,The device comprises a control unit that controls the light irradiated onto the photocurable resin composition in the container, the control unit capable of performing the following processes: irradiating the photocurable resin composition in the container with light to form a first cured layer that will be part of the 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 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 be part of the molded object, the control unit controls the process of forming the second cured layer such that the first irradiation energy density of the light irradiated onto the first portion is lower than the second irradiation energy density of the light irradiated onto the second portion. death , The control unit forms the support between the molding stage and the molded object by performing the process of forming the first hardened layer and the process of forming the second hardened layer. It is characterized by the following:

[0011] The present invention relates to a method for creating a processing program, which is used for stereolithography of a molded object, and comprises the steps of: acquiring first shape data representing the shape of the molded object; acquiring second shape data representing a support shape; and defining the relationship between the first shape data and the second shape data such that a portion of the support shape overlaps with the first portion of the shape of the molded object. The steps include: obtaining multiple layers of slice data obtained by slicing the overlapping shape of the fabricated object and the support shape at a predetermined thickness pitch; defining a second irradiation energy density of light used for fabricating the region inside the contour of the support shape for the slice data among the multiple layers of slice data that includes only the contour of the support shape; and, for the second slice data among the multiple layers of slice data in which the contour of the support shape is located inside the contour of the fabricated object, The first irradiation energy density of the light used to shape the first part is equal to the light used to shape the second part other than the first part in the shape of the fabricated object. The aforementioned The steps include defining the preceding first irradiation energy density and the preceding second irradiation energy density such that they are lower than the second irradiation energy density, With respect to slice data from the multiple layers of slice data, with respect to slice data that includes only the contour of the shape of the fabricated object, the step of defining the second irradiation energy density of light used for fabricating the region inside the contour of the shape of the fabricated object, It is characterized by having the following features.

[0012] The processing program of the present invention relates to a photocurable resin composition Irradiate with light to produce a photocurable resin composition A processing program to be executed by a computer of a stereolithography apparatus that hardens a material to form a molded object, comprising: a step of causing the computer to control the light irradiated onto the photocurable resin composition to form a first cured layer which will be part of the support; and a step of causing the computer to control the light irradiated onto the photocurable resin composition to form a second cured layer which 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 be part of the molded object. The steps include: causing the computer to control the light irradiated onto the photocurable resin composition to a second irradiation energy density, thereby forming a third cured layer only on the molded object;comprising In the step of forming the first cured layer, the computer is instructed to control the light irradiated onto the photocurable resin composition to a second irradiation energy density. In the step of forming the second cured layer, the computer is configured such that the degree of curing of the first portion is lower than the degree of curing of the second portion When forming the first portion, the light irradiated onto the photocurable resin composition is controlled to a first irradiation energy density lower than the second irradiation energy density; when forming the second portion, the light irradiated onto the photocurable resin composition is controlled to the second irradiation energy density; and in the step of forming the third cured layer, the computer is instructed to control the light irradiated onto the photocurable resin composition to the second irradiation energy density. characterized by this.

Advantages of the Invention

[0013] According to the present invention, the burden on the operator is reduced.

Brief Description of the Drawings

[0014] [Figure 1] It is a schematic cross-sectional view of a stereolithography apparatus according to an embodiment. [Figure 2] It is a schematic cross-sectional view of a molded object according to an embodiment. [Figure 3] (a) is a block diagram showing the configuration of the control system of a stereolithography apparatus according to an embodiment. (b) is a block diagram showing the configuration of a host device according to an embodiment. [Figure 4] It is a flowchart showing a method for creating a machining program according to an embodiment. [Figure 5] (a) to (d) are explanatory diagrams of a method for creating a machining program according to an embodiment. [Figure 6] (a) to (i) are explanatory diagrams of a method for manufacturing a molded object according to an embodiment. [Figure 7] It is a schematic cross-sectional view showing an enlarged view of a support removal mark of a molded object according to an embodiment and its surroundings. [Figure 8] It is a diagram showing the experimental results of Examples and Comparative Examples.

Modes for Carrying Out the Invention

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

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

[0017] The light irradiation unit 5 is configured to irradiate the photocurable resin composition 1 with light from above the container 2 toward the molding stage 3, i.e., to expose it.

[0018] The molding stage 3 functions as a base for supporting the cured product formed by the light irradiation of the light irradiation unit 5, and is positioned within the container 2 so as to be movable in the vertical direction (Z direction). The molding stage 3 is driven in the Z direction by the lifting device 4. The lifting device 4 raises and lowers the molding stage 3 in the Z direction according to the command it receives.

[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 molding stage 3. The supply device 7 includes a recoater or squeegee 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 is the wavelength of the photocurable resin composition 1 Any wavelength suitable for the polymerization reaction is acceptable. For example, if the photocurable resin composition 1 is UV curable, the wavelength is ultraviolet, and is selected from a range of approximately 200 nm to 400 nm. The wavelength of light emitted by the light source 8 is typically 405 nm or 365 nm.

[0021] The mirror unit 9 is composed of a galvanometer mirror and the like. Light emitted from the light source 8 passes through the mirror unit 9 and the lens unit 10, becoming a light spot at the liquid surface 11 of the photocurable resin composition 1 in the container 2. When the mirror unit 9 is driven, the light spot is scanned horizontally in the XY direction at the liquid surface 11. This planar scanning of the light spot allows the photocurable resin composition 1 in the container 2 to harden a portion corresponding to the shape of one layer of the molded object 21. Then, by lowering the molding stage 3 one layer at a time, multiple hardened layers can be formed.

[0022] In this embodiment, the light irradiation unit 5 is configured to scan a light spot in a planar manner, but the system is not limited to this configuration. The light irradiation unit 5 may be configured as a projector that irradiates image light onto the liquid surface 11.

[0023] Figure 2 is a schematic cross-sectional view of the molded object 21 according to the embodiment. Figure 2 shows the molded object 21 before the support 23 is removed and after the support 23 is removed. The molded object 21 has support removal marks 22 formed by removing the support 23. According to the present invention, the support removal marks 22 are formed recessed relative to the surrounding molded surface 210, preventing interference with other members. The molded surface 210 is preferably flat, but is not limited to this. The mixed layer 24 of the molded object 21 and the support 23 before the support 23 is removed from the molded object 21 is the part that becomes part of the molded object 21 and part of the support 23 when the support 23 is 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 support 23 is removed from the molded object 21. Therefore, the surface state 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] Figure 3(a) is a block diagram showing the configuration of the control system of the stereolithography apparatus 100 according to the embodiment. The stereolithography 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 composed of computers.

[0025] The host device 610 generates a processing program 630. The control device 620 obtains 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 predetermined control cycles according to 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 according to control commands received from the control device 620. The stage control unit 606 controls the lifting device 4 that drives the molding stage 3 according to control commands received from the control device 620. The stage control unit 606 also controls the supply device 7 according to 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 molding stage 3 and the supply device 7 according to the processing program 630, enabling stereolithography of the object 21 on the molding stage 3. The processing program 630 and the 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; ROM 602 and RAM 603, which are examples of storage devices; input / output interfaces IF 604 and 608; and a network interface NIF 609. The CPU 601, ROM 602, RAM 603, IF 604 and 608, and NIF 609 are connected to each other in a manner that enables data communication.

[0028] The CPU 601 acquires the machining program 630 from the host device 610 via the IF 608. The CPU 601 functions as a control unit that executes the molding control procedure according to the machining program 630 by running the application software (control program) 635. Specifically, the CPU 601 controls the light source 8 and the mirror unit 9 via the IF 604 and the light irradiation control unit 605 according to 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 according to the machining program 630.

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

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

[0031] IF604, IF608, and NIF609 can be configured based on, for example, a serial interface standard or a parallel interface standard.

[0032] Figure 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 input / output interface IF 614; and a network interface NIF 619. 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.

[0033] The CPU 611 functions as a processing unit that creates the machining program 630 by executing the 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] ROM 612 stores a creation program 640 that can be executed by CPU 611. In other words, ROM 612 constitutes a computer-readable, non-temporary recording medium that stores the creation program 640. ROM 612 may also be a rewritable storage device such as an EPROM or EEPROM. The host device 610 may also be equipped with storage such as an HDD or SSD capable of storing the creation program 640.

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

[0036] The IF614 and NIF619 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-temporary recording medium, such as a storage device or recording disk that can be supplied to a computer.

[0038] Next, the method for creating the machining program 630 using the host device 610 will be described. Figure 4 is a flowchart illustrating the method for creating the machining program 630 according to this embodiment. Figures 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 representing the shape of the printed object 40, as shown in Figure 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 printed object (printing model) desired by the user, but since support removal marks 22 are formed on the actual printed object 21, it differs slightly from the shape of the actual printed object 21. That is, the object shape data 30 is shape data of a printed object without support removal marks. The object shape data 30 may be created in the host device 610, or it may be read from an external source in the host device 610.

[0040] Furthermore, in step S120, the CPU 611 acquires multiple support shape data 31 representing the support shape 41, as shown in Figure 5(b). The support shape data 31 is an example of the second shape data. 5 (b) shows one support shape data 31. The support shape data 31 is the shape data corresponding to the support, but a part of the support shape data 31 is made to penetrate (embed) inside the shape data 30 of the molded object, as will be described later, so it is slightly different from the actual shape of the support 23 obtained. The support shape data 31 may be created in the host device 610, or it may be read from an external source by the host device 610.

[0041] To illustrate with an example of creating support shape data 31 in the host device 610, the CPU 611 determines the support placement surface 401 on which supports will be placed based on the build height, etc., for the build shape 40 defined by the build shape data 30 acquired in step S110. Then, the CPU 611 determines the spacing of the supports based on the maximum area on which the build shape can be supported by the supports, as shown in the figure. 5 (b) Create multiple support shape data 31 as shown in (b).

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

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

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

[0045] Steps S150 to S190 are steps in which the layer images 32 and 33, which consist of multiple layers created in step S140, are processed layer by layer. First, in step S150, the CPU 611 is set to n=1.

[0046] Next, in step S160, the CPU 611 determines whether or not the nth layer images 32 and 33 exist. In this case, since n=1, the CPU 611 determines whether or not the first layer images 32 and 33 exist. If the first layer images 32 and 33 exist (S160:YES), the CPU 611 obtains the first layer image from the multiple layer images 32 and multiple layer images 33 created in step S140.

[0047] If the nth layer images 32 and 33 are not present (S160: NO), the CPU 611 proceeds to the process of creating the machining program 630 in step S200. The machining program 630 is created, for example, in a file format.

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

[0049] In the example shown in Figure 5(d), the first layer lacks the contour of the fabricated object shape 40, so there is no overlapping region between the fabricated object shape 40 and the support shape 41, and only the region R1 inside the contour of the support shape 41 exists. Therefore, the CPU 611 defines the exposure conditions, i.e., the light irradiation energy density E2, for the region R1 of the first layer. That is, it defines the light irradiation energy density E2 when forming the support 23 in the first layer. For example, the power of the light source 8 and the scanning speed of the light are defined as the light irradiation energy density E2. The light irradiation energy density E2 is defined so that the degree of curing (curing reaction rate) of the photocurable resin composition 1 reaches 100%, i.e., the photocurable resin composition 1 is sufficiently cured.

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

[0051] Since the second layer also lacks the contour of the printed object shape 40, there is no overlapping region between the printed object shape 40 and the support shape 41, and only the contour of the support shape 41 exists. Therefore, the CPU 611 defines the exposure conditions, 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 region R0 inside the contour of the printed object shape 40 and the overlapping region R1 inside the contour of the support shape 41. The overlapping region is region R1. In step S170, the CPU 611 creates a difference image 34. The difference image 34 is region R2, which is obtained by deleting the region R1 inside the contour of the support shape 41 from the region R0 inside the contour of the printed object shape 40.

[0053] The CPU 611 defines exposure conditions, i.e., light irradiation energy density E2, for the third layer region R2, and defines lower exposure conditions, i.e., irradiation energy density E1, which is lower than light irradiation energy density E2, for the third layer region R1. The ratio of irradiation energy density E1 to 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. Irradiation energy density E1 is an example of a first irradiation energy density, and irradiation energy density E2 is an example of a second irradiation energy density.

[0054] In the fourth layer, there is an overlapping region R0 inside the contour of the fabricated object shape 40 and the overlapping region R1 inside the contour of the support 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 of the fourth layer, and defines a lower exposure condition, i.e., an irradiation energy density E1 lower than the light irradiation energy density E2, for region R1 of the fourth layer.

[0055] Thus, in step S170, the CPU 611 defines irradiation energy densities E1 and E2 such that the irradiation energy density E1 used for fabricating part 402 is lower than the irradiation energy density E2 used for fabricating part 403.

[0056] Since the fifth layer lacks the contour of the support shape 41, there is no overlapping region between the fabricated object shape 40 and the support shape 41, and only the contour of the fabricated object shape 40 exists. Therefore, the CPU 611 defines the exposure conditions, i.e., the light irradiation energy density E2, for the region R0 of the fifth layer.

[0057] Since the sixth layer lacks the contour of the support shape 41, there is no overlapping region between the fabricated object shape 40 and the support shape 41, and only the contour of the fabricated object shape 40 exists. Therefore, the CPU 611 defines the exposure conditions, i.e., the light irradiation energy density E2, for the region R0 of the sixth layer.

[0058] When definitions are completed for all layers (S160:YES), the CPU 611 creates a file as a processing program 630 that defines the layer images 32 (excluding the 3rd and 4th layers), layer images 33, difference images 34, exposure conditions, and the operation of the molding stage 3. The processing program 630 is sent to the control device 620 and used to fabricate the object 21.

[0059] The following describes a manufacturing method for producing a molded object 21 by curing a photocurable resin composition 1 using a stereolithography apparatus 100. The CPU 601 of the control device 620 executes a molding control procedure according to the processing program 630. The following description will use the case where the first to sixth cured layers are formed according to the processing program 630 as an example.

[0060] Figures 6(a) to 6(i) are explanatory diagrams of each step in the manufacturing method of the molded object 21 according to the embodiment. The molded object 21 is formed by curing the photocurable resin composition 1 through the following steps.

[0061] First, fill the container 2 shown in Figure 1 with the uncured photocurable resin composition 1, and adjust the position of the printing stage 3 in the Z direction so that the distance between the printing stage 3 and the liquid surface 11 is equal to the thickness Δt. Each time the printing stage 3 is lowered, the liquid surface 11 is leveled by the supply device 7 to ensure stability. When using a photocurable resin composition 1 that shrinks during curing, it is recommended to set the distance between the printing stage 3 and the liquid surface 11 to a value equal to the Δt of the slice data plus the shrinkage amount.

[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 with an irradiation energy density E2, thereby forming the first cured layer A1, which will become a part 221 of the support 23.

[0063] Next, in step S302 shown in Figure 6(b), the CPU 601 controls the molding stage 3 to lower it by a thickness Δt. Then, the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E2, thereby forming a second cured layer A2 on the cured layer A1, which will become a part 222 of the support 23. Cured layer A2 is an example of the first cured layer.

[0064] Next, in step S303 shown in Figure 6(c), the CPU 601 controls the molding stage 3 to lower it by a thickness Δt. The CPU 601 then controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E1, thereby forming a portion 211 on the cured layer A2 that overlaps with the cured layer A2 (part 222) when viewed in the Z direction, which is the thickness direction of the cured layer A2.

[0065] Next, in step S304 shown in Figure 6(d), the light irradiation unit 5 is controlled to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E2 around portion 211, thereby forming portion 212 that does not overlap with the cured layer A2 (portion 222) when viewed in the Z direction. That is, portion 212 is formed after portion 211 is formed.

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

[0067] In steps S303 and S304, by making the irradiation energy density E1 of the light irradiated when forming part 211 lower than the irradiation energy density E2 of the light irradiated when forming part 212, the degree of curing of part 211 becomes lower than the degree of curing of part 212. Note that the layer with a lower degree of curing is not limited to one, but may be formed in succession of multiple layers.

[0068] In step S305 shown in Figure 6(e), the CPU 601 controls the molding stage 3 to lower it by a thickness Δt. The CPU 601 then controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E1, thereby forming a portion 213 on portion 211 that overlaps with portions 211 and 222 when viewed in the Z direction.

[0069] Next, in step S306 shown in Figure 6(f), the CPU 601 controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E2 around portion 213, thereby forming portion 214 that does not overlap with portions 211 and 222 when viewed in the Z direction. That is, portion 214 is formed after portion 213 is formed.

[0070] In steps S305 and S306 shown in Figures 6(e) and 6(f), a fourth hardened layer A4 is formed, including portions 213 and 214. Portion 214 becomes part of the fabricated object 21. Portion 214 is located around portion 213.

[0071] In steps S305 and S306, by making the irradiation energy density E1 of the light irradiated when forming part 213 lower than the irradiation energy density E2 of the light irradiated when forming part 214, the degree of curing of part 213 becomes lower than the degree of curing of part 214.

[0072] Next, in step S307 shown in Figure 6(g), the CPU 601 controls the molding stage 3 to lower it by a thickness Δt. The CPU 601 then controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E2, thereby forming a fifth hardened layer A5 on the hardened layer A4, which will become a part 215 of the molded object 21.

[0073] Next, in step S308 shown in Figure 6(h), the CPU 601 controls the molding stage 3 to lower it by a thickness Δt. The CPU 601 then controls the light irradiation unit 5 to irradiate the photocurable resin composition 1 with light L with an irradiation energy density E2, thereby forming a sixth hardened layer A6 on the hardened layer A5, which will become a part 216 of the molded object 21.

[0074] As described above, by irradiating only the necessary parts with the light L emitted from the light source 8, the photocurable resin composition 1 on the molding stage 3 can be selectively cured. As described above, by repeating the downward movement of the molding stage 3 and the irradiation of light onto the molding stage 3 or the cured object on the molding stage 3, a molded object 21 can be fabricated on the molding stage 3. Although the explanation has been given using the case of forming six cured layers A1 to A6 as an example, the number of layers in the fabrication of the molded object and support is not limited to the above example.

[0075] Next, as shown in Figure 6(i), the printed object 21 is removed from the stereolithography apparatus 100 for post-processing. Specifically, the printing stage 3, to which the printed object 21 is fixed via the support 23, is removed from the container 2, and the printed body, including the printed object 21 and the support 23, is separated from the printing stage 3 using a tool such as a scraper or spatula. Next, the uncured photocurable resin composition 1 adhering to the printed object 21 and the support 23 is removed using a solvent such as ethanol or IPA. At this time, an ultrasonic cleaner can be used to easily remove the photocurable resin composition 1 in a short time.

[0076] Next, load is applied to the support 23 connected to the build surface 210 of the printed object 21 to remove the support 23 from the printed object 21. This removal can be done manually by the operator, or by the operator using tools such as a scraper.

[0077] In Figure 6(i), the mixed layer 24 between the molded object 21 and the support 23 is less hardened than the rest of the layer, making it more prone to fracture during the removal process of the support 23 from the molded object 21. This removal process creates the support removal marks 22 shown in Figure 7 on the molded object 21. Before the support 23 is removed from the molded object 21, the mixed layer 24 is embedded in the molded object 21. Therefore, before the support 23 is removed from the molded object 21, the mixed layer 24 is either not exposed to the outside or is only slightly exposed. When the support 23 is removed from the molded object 21, the mixed layer 24 fractures and becomes part of the molded object 21 and part of the support 23. Figure 7 is a schematic cross-sectional view of the support removal marks 22 and their surroundings on the molded object 21, magnified. The support removal marks 22 have a concave shape that is lower than the molded surface 210 of the molded object 21.

[0078] The support removal marks 22 are formed in a gently concave shape, i.e., a bowl shape, where the average line of the roughness curve in the cross-section is gently curved. 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 the light of irradiation energy density E1 described above is preferably 0.5 mm or less, and more preferably 0.2 mm or less. This effectively prevents the fabricated object 21 from being damaged when the supports 23 are removed from the fabricated object 21.

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

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

[0081] The shape of the support removal mark 22 is determined by the cross-sectional shape of the support 23, but considering ease of removal, it is preferable to make it circular in plan view. That is, the cross-sectional shape of the support removal mark 22 is preferably bowl-shaped.

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

[0083] As described above, according to this embodiment, when the support 23 is removed, the support removal marks 22 become concave, thus reducing the labor required to smooth out the convex support removal marks and alleviating the burden on the worker. This improves work efficiency and reduces the manufacturing cost of the molded object 21.

[0084] [Examples] Examples 1 and 2 will be described. Using the stereolithography apparatus 100 shown in Figure 1, a fabrication experiment was conducted to create an object 21 with a width of 50 mm, a depth of 30 mm, and a height of 10 mm in an environment of approximately 25°C. The illumination light had a wavelength of 405 nm and a maximum illuminance of 10 mW / cm². 2 Ultraviolet light was used. The size of container 2 was approximately 70 mm x 50 mm x 30 mm. Light was irradiated using a DMD element with a resolution of 1920 pixels x 1080 pixels to cure the photocurable resin composition 1. The size of the molding stage 3 was 60 mm x 50 mm. The photocurable resin composition 1 was a material made by adding an inorganic filler to a mixture of epoxy and acrylic.

[0085] The printing conditions will be explained. The irradiation energy density E2 of the printed object 21 and support 23 will be 80 mJ / cm². 2 The irradiation energy density E1 of the mixed layer 24 of the fabricated object 21 and the support 23 was set to 30 mJ / cm². 2 (Example 1) and 50 mJ / cm 2 The model was fabricated using two patterns as shown in (Example 2). After the fabrication process was completed, the worker manually removed the support structures 23.

[0086] After removing the support 23, the fabricated object 21 was washed with ethanol to remove any excess resin liquid adhering to it, dried in a fume hood 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 printed object and support, and the irradiation energy density E2 of the printed object and support is 80 mJ / cm³. 2 In the comparative example, the support removal marks were evaluated in the same manner as in Examples 1 and 2.

[0088] These evaluation results are shown in Figure 8. In the evaluation results, A: the support removal marks are concave relative to the surface of the printed object, and B: the support removal marks are convex relative to the surface of the printed object.

[0089] As shown in Figure 8, in the comparative example, the support removal marks were convex relative to the fabricated surface of the object, and the size of the convex shape ranged from 150 μm to 250 μm.

[0090] In Examples 1 and 2, the mixed layer 24 was 30 mJ / cm³. 2 More than 50mJ / cm 2 When formed with the following irradiation energy density E1, the fabricated object 21 could be manufactured without defects, and the support removal marks 22 were concave relative to the fabricated surface 210 of the fabricated object 21. At this time, the ratio of irradiation energy density E1 to irradiation energy density E2 (E1 / E2) was between 0.375 and 0.625. The maximum size of the support removal marks 22 was confirmed to be 190 μm.

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

[0092] The present invention is not limited to the embodiments described above, 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 preferred 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 implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0094] In the above-described embodiment, the host device 610 and the control device 620 are configured as separate computers, but the invention is not limited to this configuration, and for example, they may be configured as a single computer. In this case, the creation and execution of the machining program 630 can be performed on a single computer.

[0095] The above disclosures of embodiments include the following configurations and methods.

[0096] (Composition 1) A molded object formed from a cured product of a photocurable resin composition, It has a molded surface and support removal marks that are recessed relative to the molded surface, The surface roughness of the support removal marks is rougher than the surface roughness of the molded surface. A sculptural object characterized by the following features.

[0097] (Configuration 2) The arithmetic mean roughness Ra of the support removal trace is between 10 μm and 15 μm. The shaped object described in configuration 1, which is characterized by the above.

[0098] (Composition 3) The depth of the support removal marks is 0.5 mm or less. A molded object according to configuration 1 or 2, characterized by the above.

[0099] (Composition 4) The depth of the support removal marks is 0.2 mm or less. A molded object according to any one of the configurations 1 to 3, characterized by the features described above.

[0100] (Composition 5) The aforementioned support removal marks are bowl-shaped. A molded object according to any one of the configurations 1 to 4, characterized by the features described above.

[0101] (Composition 6) The diameter of the support removal marks is between 0.3 mm and 1.0 mm. The molded object according to configuration 5, characterized by the features described above.

[0102] (Composition 7) The ratio of the degree of hardening of the portion of the molded object where the support removal marks are formed to the degree of hardening of the portion where the molded surface is formed is 0.4 or more and 0.8 or less. A molded object according to any one of the configurations 1 to 6, characterized by the features described above.

[0103] (Method 8) A method for manufacturing a molded object by curing a photocurable resin composition, The steps include irradiating a photocurable resin composition with light to form a first cured layer that will be part of the support, The process includes the step of irradiating a photocurable resin composition with light to form a second cured layer which 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 becomes part of the molded object. In the step of forming the second cured layer, the second cured layer is formed such that the degree of curing of the first portion is lower than the degree of curing of the second portion. A method for manufacturing molded objects, characterized by the following:

[0104] (Method 9) In the step of forming the second hardened layer, the first irradiation energy density of the light irradiated to the first portion is lower than the second irradiation energy density of the light irradiated to the second portion. A method for manufacturing a molded object as described in Method 8.

[0105] (Method 10) The ratio of the first irradiation energy density to the second irradiation energy density is 0.3 or more and 0.7 or less. A method for manufacturing a molded object as described in method 9.

[0106] (Method 11) The process further comprises the step of removing the support from the molded object, The step of removing the support creates a support removal mark on the fabricated object that is recessed relative to the fabricated surface. A method for manufacturing a molded object according to any one of methods 8 to 10.

[0107] (Composition 12) A stereolithography apparatus for curing a photocurable resin composition to form a molded object, A container for storing a photocurable resin composition, The container comprises a control unit that controls the light irradiated onto the photocurable resin composition inside 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 be part of the support, The process of irradiating the photocurable resin composition in the container with light to form a second cured layer comprising 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 becomes part of the molded object, is possible. The control unit, In the process of forming the second hardened layer, 1 Light shining on a part 1 The irradiation energy density is 2 Light shining on a part 2nd Control it so that it is lower than the irradiation energy density. A stereolithography apparatus characterized by the following features.

[0108] (Method 13) A method for creating a processing program used for stereolithography of a molded object, A step of obtaining first shape data that shows the shape of the molded object, A step to obtain second shape data showing the support shape, The steps include defining the relationship between the first shape data and the second shape data such that a portion of the support shape overlaps with the first portion of the shape of the fabricated object, The method comprises the step of defining the first irradiation energy density and the second irradiation energy density such that the first irradiation energy density of light used to shape the first part is lower than the second irradiation energy density of light used to shape the second part other than the first part in the shape of the fabricated object. A method for creating a processing program characterized by the above.

[0109] (Composition 14) A program for causing a computer to execute the method for creating a processing program described in Method 13.

[0110] (Composition 15) A processing program to be executed by the computer of a stereolithography apparatus that cures a photocurable resin composition to form a molded object, The steps include: causing the computer to control the light irradiated onto the photocurable resin composition to form a first cured layer that will be part of the support; The process includes the step of causing the computer to control the light irradiated onto the photocurable resin composition to form a second cured layer which 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 becomes part of the molded object. In the step of forming the second hardened layer, the computer is instructed to form the second hardened layer such that the degree of hardening of the first portion is lower than the degree of hardening of the second portion. A processing program characterized by the following features.

[0111] (Composition 16) A computer-readable recording medium containing the creation program described in Configuration 14.

[0112] (Composition 17) A computer-readable recording medium on which the processing program described in configuration 15 is recorded. [Explanation of symbols]

[0113] 1…Photocurable resin composition, 21…Printed object, 22…Support removal marks, 23…Support, 100…Stereolithography apparatus, 630…Processing program, 640…Creation program

Claims

1. A molded object formed from a cured product of a photocurable resin composition, It has a molded surface and support removal marks that are recessed relative to the molded surface, The aforementioned molded object has a first surface, The molded surface and the support removal marks are provided on the first surface. The surface roughness of the support removal marks is rougher than the surface roughness of the molded surface. A sculptural object characterized by the following features.

2. The arithmetic mean roughness Ra of the support removal marks is 10 μm or more and 15 μm or less. The molded object according to claim 1, characterized in that way.

3. The depth of the support removal marks is 0.5 mm or less. The molded object according to feature 1.

4. The depth of the support removal marks is 0.2 mm or less. The molded object according to feature 1.

5. The aforementioned support removal marks are bowl-shaped. The molded object according to feature 1.

6. The diameter of the support removal marks is between 0.3 mm and 1.0 mm. The molded object according to feature 5.

7. The ratio of the degree of hardening of the portion of the molded object where the support removal marks are formed to the degree of hardening of the portion where the molded surface is formed is 0.4 or more and 0.8 or less. The molded object according to any one of claims 1 to 6.

8. A method for manufacturing a molded object, comprising curing a photocurable resin composition stored in a container by irradiating it with light to form a molded object on a molding stage, The process involves irradiating a photocurable resin composition with light to form a first cured layer that will serve as part of the support, The process includes the step of irradiating a photocurable resin composition with light to form a second cured layer which 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 becomes part of the molded object. In the step of forming the second cured layer, the second cured layer is formed such that the degree of curing of the first portion is lower than the degree of curing of the second portion. The support is formed between the molding stage and the molded object. A method for manufacturing molded objects, characterized by the following:

9. The method further comprises the step of irradiating a photocurable resin composition with light to form a third cured layer only on the molded object. The method for manufacturing a molded object according to feature 8.

10. In the step of forming the first cured layer, the light irradiated onto the photocurable resin composition is controlled to a second irradiation energy density, In the step of forming the second cured layer, when forming the first portion, the light irradiated onto the photocurable resin composition is controlled to a first irradiation energy density lower than the second irradiation energy density, and when forming the second portion, the light irradiated onto the photocurable resin composition is controlled to the second irradiation energy density. In the step of forming the third cured layer, the light irradiated onto the photocurable resin composition is controlled to the second irradiation energy density. The method for manufacturing a molded object according to feature 9.

11. The 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 molded object according to feature 10.

12. The process further comprises the step of removing the support from the molded object, The step of removing the support creates a support removal mark on the fabricated object that is recessed relative to the fabricated surface. A method for manufacturing a molded object according to any one of claims 8 to 11.

13. A stereolithography apparatus for forming a 3D object by irradiating a photocurable resin composition with light to cure the photocurable resin composition, A container for storing a photocurable resin composition, A molding stage is placed inside the aforementioned container, The container comprises a control unit that controls the light irradiated onto the photocurable resin composition inside 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 be part of the support, The process of irradiating the photocurable resin composition in the container with light to form a second cured layer comprising 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 becomes part of the molded object, is possible. The control unit controls the process of forming the second hardened layer such that the first irradiation energy density of the light irradiated to the first portion is lower than the second irradiation energy density of the light irradiated to the second portion. The control unit performs the process of forming the first hardened layer and the process of forming the second hardened layer to form the support between the molding stage and the molded object. A stereolithography apparatus characterized by the following features.

14. The control unit is capable of further performing a process of irradiating the photocurable resin composition in the container with light to form a third cured layer consisting only of the molded object. The stereolithography apparatus according to feature 13.

15. The control unit is In the process of forming the first cured layer, the light irradiated onto the photocurable resin composition is controlled to the second irradiation energy density, In the process of forming the third cured layer, the light irradiated onto the photocurable resin composition is controlled to the second irradiation energy density. The stereolithography apparatus according to feature 14.

16. A method for creating a processing program used for stereolithography of a molded object, A step of acquiring first shape data that shows the shape of the molded object, A step of obtaining second shape data that shows the support shape, The steps include defining the relationship between the first shape data and the second shape data such that a portion of the support shape overlaps with the first portion of the shape of the fabricated object, The steps include: obtaining slice data of multiple layers obtained by slicing the overlapping shapes of the fabricated object and the support shape at a predetermined thickness pitch; With respect to the slice data among the multiple layers of slice data, with respect to the slice data that includes only the contour of the support shape, the step of defining a second irradiation energy density of light used for fabricating the region inside the contour of the support shape, With respect to the second slice data among the multiple layers of slice data in which the contour of the support shape is located inside the contour of the shape of the fabricated object, the steps of defining the first irradiation energy density and the second irradiation energy density such that the first irradiation energy density of the light used to fabricate the first part is lower than the second irradiation energy density of the light used to fabricate the second part other than the first part in the shape of the fabricated object, The method comprises the step of defining the second irradiation energy density of light used to shape the region inside the contour of the shape of the fabricated object, with respect to the slice data among the multiple layers of slice data that includes only the contour of the shape of the fabricated object. A method for creating a processing program characterized by the above.

17. A creation program for causing a computer to execute the method for creating a processing program described in claim 16.

18. A processing program to be executed by the computer of a stereolithography apparatus that irradiates a photocurable resin composition with light to cure the photocurable resin composition and form a molded object, The steps include: causing the computer to control the light irradiated onto the photocurable resin composition to form a first cured layer that will be part of the support; The steps include: causing the computer to control the light irradiated onto the photocurable resin composition to form a second cured layer which 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 becomes part of the molded object; The process includes the step of causing the computer to control the light irradiated onto the photocurable resin composition to a second irradiation energy density, thereby forming a third cured layer only on the molded object. In the step of forming the first cured layer, the computer is instructed to control the light irradiated onto the photocurable resin composition to a second irradiation energy density. In the step of forming the second cured layer, the computer is instructed to control the light irradiated onto the photocurable resin composition to a first irradiation energy density lower than the second irradiation energy density when forming the first portion, so that the degree of curing of the first portion is lower than the degree of curing of the second portion, and to control the light irradiated onto the photocurable resin composition to the second irradiation energy density when forming the second portion. In the step of forming the third cured layer, the computer is instructed to control the light irradiated onto the photocurable resin composition to the second irradiation energy density. A processing program characterized by the following features.

19. A computer-readable recording medium that stores the creation program described in claim 17.

20. A computer-readable recording medium that stores the processing program described in claim 18.

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