Method for manufacturing photocurable manufacturing object

Abstract

To provide a method for manufacturing photo-curing production object that enables easy separation of a production object from a support part.SOLUTION: A method for manufacturing a photo-curing production object includes: a support part molding step of molding a support part 51 provided with a strongly cured part 55 and a weakly cured part 56 that is softer than the strongly cured part 55; a production object molding step in which a production object 61 is molded so that the weakly cured part 56 is interposed between the strongly cured part 55 and the production object 61; and a separation step of separating the production object 61 from the support part 51 at a position of the weakly cured part 56.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a photocurable object, for example, by a liquid vat photopolymerization method. [Background technology]

[0002] Modeling devices that use a liquid vat photopolymerization method to form three-dimensional objects, known as 3D printers, are already widely known (see, for example, Patent Document 1). A typical modeling device has the function of stacking layers of cured resin or the like to form a three-dimensional object. The liquid vat photopolymerization method includes a free liquid level method in which a base is placed in a vat filled with resin liquid, and light is irradiated from above onto the surface of the resin liquid to harden the resin liquid on the base, and the base is then lowered; and a restricted liquid level method in which the bottom of the vat is made light-transmitting and light is irradiated from below to harden the resin liquid below the base, and the base is then raised.

[0003] Patent Document 2 also discloses that a desired object to be manufactured is obtained by separating the base and the support, and finishing the surface of the base by polishing, painting, etc. Generally, the support has the same hardness as the object to be manufactured so as to reliably support the object to be manufactured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-286058 [Patent Document 2] Japanese Patent Application Publication No. 2018-47623 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the current situation is that the finishing process of polishing the surface of the workpiece from which the support has been separated is a very laborious and time-consuming process. In particular, in the liquid vat photopolymerization method, since the workpiece 100 and the support 101 are made of the same hard resin material as shown in Figure 7, roughness remains on the surface when the workpiece 100 and the support 101 are separated, requiring a sophisticated finishing process.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing a photocurable object, which allows for easy separation of the object part and the support part. [Means for solving the problem]

[0007] The present invention relates to a method for manufacturing a photocurable object, which involves irradiating a photocurable liquid photocurable material contained in a predetermined liquid tank with predetermined light to harden the liquid photocurable material in layers, thereby forming hardened layers in the liquid tank, and stacking the hardened layers to three-dimensionally mold an object to be manufactured with a desired shape and a support part that supports the object to be manufactured, and then separating the molded object to be manufactured from the support part to obtain a desired object to be manufactured based on the object to be manufactured.The method includes a step of forming a hardened layer for a support part as a hardened layer that constitutes the support part, and the hardened layer for the support part has a strongly hardened part with a predetermined hardness and a peripheral part of the strongly hardened part that is relatively softer than the strongly hardened part due to an incomplete hardening state and is therefore capable of supporting the object to be manufactured. a support part forming step in which a weakly hardened portion having a hardness sufficient for the object to be manufactured is formed at the tip of the support part on the object to be manufactured, the tip of which is formed by stacking hardened layers for the support part, and the weakly hardened portion is provided at the tip of the support part on the object to be manufactured; a manufacturing part forming step in which a hardened layer for the object to be manufactured is formed as a hardened layer that constitutes the object to be manufactured supported by the support part, and the object to be manufactured is formed by stacking hardened layers for the object to be manufactured at the tip of the support part, so that the weakly hardened portion is interposed between the object to be manufactured and the strongly hardened portion in the support part; and a separation step in which the object to be manufactured and the support part are separated from each other at the position of the weakly hardened portion in the support part.

[0008] In this configuration, a weakly hardened portion is intentionally left in an incompletely hardened state when forming the support portion, and the weakly hardened portion is interposed between the object portion and the strongly hardened portion that essentially functions to support the object portion. Therefore, when separating the object portion from the support portion, the weakly hardened portion becomes a so-called easily breakable portion, making the separation process extremely easy. Furthermore, depending on the hardening state of the weakly hardened portion, it is possible to separate the object portion from the support portion so that the object portion peels cleanly from the weakly hardened portion. Furthermore, cracks and scratches are less likely to occur on the surface of the object portion at the separation point than in the past, resulting in the advantage of simplifying or eliminating subsequent processes such as polishing. [Effects of the Invention]

[0009] The method for producing a photocurable object of manufacture of the present invention has the excellent effect of facilitating separation of the object part and the support part. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating a modeling system according to an embodiment. [Figure 2] FIG. 10(a) shows one aspect of the process of forming the support part, and FIG. 10(b) is an explanatory diagram showing the process of forming the support part following on from FIG. [Figure 3] FIG. 10 is an explanatory diagram showing an enlarged view of a boundary portion between a support portion and a manufacturing target portion. [Figure 4] FIG. 10 is an explanatory view showing a state in which the workpiece portion is separated from the support portion. [Figure 5] FIG. 10 is an explanatory diagram showing an enlarged view of a boundary portion between a support portion and a manufacturing target portion in another example. [Figure 6] FIG. 10 is an explanatory view showing a state in which the workpiece portion is separated from the support portion in another example. [Figure 7] FIG. 10 is an explanatory diagram showing a boundary portion between a support portion and a target object portion in a conventional modeling method. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, specific examples of the method for producing a photocurable object of manufacture according to the present invention will be described in detail. Note that the present invention is not limited to the examples shown below, and appropriate design modifications are possible.

[0012] The modeling system 1 uses a 3D printer that obtains a manufacturing object by the free surface method, and as shown in FIG. 1, includes a resin liquid tank unit 10 that contains a photocurable resin liquid R.

[0013] It should be noted that known resin materials can be used as the photocurable resin liquid R, and other photocurable materials can also be used instead. The liquid photocurable material according to the present invention is constituted by the resin liquid R. The resin liquid tank 10 also constitutes the liquid tank according to the present invention.

[0014] A plate-like movable base 20 that is movable up and down is disposed within the resin liquid tank 10. The upper surface of the movable base 20 serves as a surface 21 on which a cured layer is formed.

[0015] Meanwhile, a light irradiation unit 30 is provided above and outside the resin liquid tank 10, irradiating light to cure the resin liquid R. The light irradiation unit 30 may be configured, for example, to irradiate light from multiple light sources with different performance, or to irradiate light with different characteristics by setting multiple irradiation conditions for a single light source, or may have other configurations. The light irradiation unit 30 of this embodiment includes a first light source that irradiates wide-area irradiation light α (first irradiation light) to cure a major portion of the cured layer occupying a wide area, and a second light source that irradiates outer edge irradiation light β (second irradiation light) to cure the outer edge of the major portion of the cured layer, as described below. The wide-area irradiation light α preferably has a relatively larger beam diameter and a relatively smaller output than the narrow-area outer edge irradiation light β. The configuration of the light irradiation unit 30 is not limited to this, and other configurations may also be used.

[0016] The operations of the movable base unit 20 and the light irradiation unit 30 are controlled by a control unit (not shown). For example, the control unit can be configured by a so-called central processing unit.

[0017] Next, an outline of a modeling procedure using the modeling system 1 will be described.

[0018] 2(a), the light irradiation unit 30 irradiates the liquid surface S of the resin liquid R filled above the movable base unit 20 with light to partially harden the resin liquid R, and the movable base unit 20 is then lowered, repeatedly forming support parts 51 and 52 on the hardened layer formation surface 21. The process of forming the support parts 51 and 52 corresponds to the support part forming process according to the present invention.

[0019] Then, once the support parts 51, 52 of predetermined dimensions have been formed, as shown in Fig. 2(b), the object part 61 is formed on the upper part of the support parts 51, 52. The process of forming the object part 61 corresponds to the object part forming process according to the present invention.

[0020] Incidentally, since the dimensions of each support part 51, 52 differ depending on the desired shape of the workpiece part 61, multiple support part formation processes and workpiece part formation processes are performed in parallel for a single object. Therefore, the end timing of each support part formation process and the start and end timing of each workpiece part formation process differ for each position. For example, as shown in FIG. 2(b), the end timing of the support part formation process corresponding to the first support part 51 is earlier than the end timing of the support part formation process corresponding to the second support part 52, which is taller than the first support part 51, and the end timings of the support part formation processes differ from each other.

[0021] Then, when the to-be-manufactured part 61 of the desired shape is formed, the entire modeling process is completed, and then the shaped object is removed from the resin liquid tank part 10, and the to-be-manufactured part 61 is separated from the supports 51, 52. The separated to-be-manufactured part 61 is then subjected to a finishing process such as polishing as appropriate, to obtain the to-be-manufactured product W.

[0022] Next, the internal structure of the support parts 51 and 52 formed in the support part forming step will be described in detail.

[0023] As shown in Fig. 3, the support part 51 formed in the support part forming step is formed by sequentially stacking support part hardened layers as hardened layers constituting the support part 51, and has a structure including a strongly hardened part 55 which is the main part, and a weakly hardened part 56 which is formed thinly on the outer periphery (surface layer) of the strongly hardened part 55 and is softer than the strongly hardened part 55 but has enough hardness to support the object part 61. In other words, the weakly hardened part 56 is provided at the tip of the support parts 51, 52 which have been formed to a predetermined dimension. The weakly hardened part 56 is in an incompletely hardened state compared to the strongly hardened part 55 and the object part 61, strength Hardened part 5 5 It has the property of breaking more easily than strength Hardened part 5 5 is formed to have the same hardness as the object 61 .

[0024] Incidentally, the strongly cured portions 55 and the weakly cured portions 56 having appropriate hardness and thickness can be formed by appropriately determining the properties (laser diameter, curing time, etc.) of the light irradiated from the light irradiating unit 30 and the resin material. For example, different light sources may be used for forming the support portions 51, 52 and for forming the object portion 61, and the irradiation conditions for each light source may be different. Note that, for example, by increasing the scanning speed of the light irradiated from the light irradiating unit 30, the irradiation time required to achieve the desired cured state is shortened, and conversely, by slowing the scanning speed, the irradiation time required to achieve the desired cured state is lengthened.

[0025] In the manufacturing object forming process, a hardened layer for the manufacturing object is laminated and formed at the tip of the support parts 51, 52 to form the manufacturing object part 61, and a weakly hardened part 56 comes to be interposed between the manufacturing object part 61 and the strongly hardened part 55 in the support parts 51, 52.

[0026] After the resin liquid R has cured, the resulting shaped object, consisting of the support portions 51, 52 and the to-be-manufactured portion 61, is removed from the resin liquid tank 10. As shown in FIG. 4, the to-be-manufactured portion 61 is then separated from the support portions 51, 52 at the weakly cured portion 56. Similar separation operations are performed for the other support portions (not shown). The to-be-manufactured portion 61 thus obtained is then subjected to a predetermined post-process (e.g., polishing) to obtain the desired to-be-manufactured product W. The process of separating the to-be-manufactured portion 61 from the support portions 51, 52 corresponds to the separation process according to the present invention.

[0027] The to-be-manufactured object W obtained in this manner can be easily separated from the support parts 51, 52 because the boundary between the to-be-manufactured object W and the support parts 51, 52 is the weakly hardened part 56. Furthermore, the polishing work involves polishing a part that is softer than the to-be-manufactured object W, which significantly reduces the workload and shortens the work time. Furthermore, by appropriately setting the wavelength and irradiation time of the light irradiated from the light irradiating part 30, it is no longer necessary to polish the to-be-manufactured object part 61, which would normally be required.

[0028] Another example is proposed. That is, in the final stage of the support portion forming process, it is possible to irradiate the laser beam with a relatively narrow diameter for a relatively long period of time, thereby forming a shape in which the to-be-manufactured portion 61 rests on the tip of the weakly cured portion 56, as shown in Fig. 5. In this configuration, if the contact area between the weakly cured portion 56 and the to-be-manufactured portion 61 is made as small as possible, then in the separation process, the to-be-manufactured portion 61 can be separated from the weakly cured portion 56 simply by washing away the resin liquid R, as shown in Fig. 6, and the to-be-manufactured portion W can be obtained without requiring subsequent processes such as polishing.

[0029] Furthermore, in the support portion forming process, when the weakly cured portion 56 is formed on the upper end side of the strongly cured portion 55 along the stacking direction of the cured layers, a period of time during which light is not irradiated may be intentionally set up immediately before the transition from the period during which light is irradiated to form the strongly cured portion 55 to the period during which light is not irradiated immediately before the transition to the manufacturing object portion forming process, thereby performing a non-irradiation process in which the weakly cured portion 56, which is in an incompletely cured state, is formed by utilizing the swelling of the strongly cured portion 55, taking advantage of the effect of light curing of the strongly cured portion 55.

[0030] That is, for example, as shown in Figure 5, the configuration may be such that a weakly hardened portion forming section L2 in which a weakly hardened portion 56 is formed in a non-irradiation process is formed between a strongly hardened portion forming section L1 in which a strongly hardened portion 55 and a weakly hardened portion 56 are formed in a support portion forming process and a manufacturing object portion section L3 in which a manufacturing object portion 61 is formed in a manufacturing object portion forming process.

[0031] The present invention can also be applied to a molding system that molds an object by the regulated liquid level method instead of the free liquid level method. However, since it may be difficult to form the weakly hardened portion 56 at the tip of the support portion in the regulated liquid level method, it is preferable to use the free liquid level method.

[0032] In addition, the dimensions and shapes of each part can be freely selected as appropriate. [Explanation of symbols]

[0033] 1 Modeling System 10 Resin liquid tank section 20 Base 21 Hardened layer forming surface 30 Light source section 51,52 Support part 55 Hardened part 56 Slightly hardened part 61 Manufacturing Objects Department R Resin liquid S liquid level W Manufacturing Object

Claims

[Claim 1] A method for manufacturing a photocurable object, comprising: irradiating a photocurable liquid photocurable material contained in a predetermined liquid tank with predetermined light to harden the liquid photocurable material in layers, thereby forming hardened layers in the liquid tank; stacking the hardened layers to three-dimensionally mold an object to be manufactured having a desired shape and a support part for supporting the object to be manufactured; and separating the molded object to be manufactured from the support part to obtain a desired object to be manufactured based on the object to be manufactured, a support part forming step in which a hardened layer for the support part is formed as a hardened layer constituting the support part, the hardened layer for the support part being formed by a hardened part having a predetermined hardness and a weakly hardened part at the outer periphery of the hardened part, the hardened part being relatively softer than the hardened part and having a hardness capable of supporting the object part, and the weakly hardened part being provided at the tip of the support part on the side of the object part to be manufactured, which is formed by stacking the hardened layers for the support part; a manufacturing object part forming step, which is a step of forming a hardened layer for the manufacturing object part as a hardened layer constituting the manufacturing object part supported by the support part, in which the manufacturing object part is formed by stacking the hardened layer for the manufacturing object part on the tip part of the support part, and the weakly hardened part is interposed between the manufacturing object part and the strongly hardened part in the support part; a separation step of separating the object portion and the support portion from the position of the weakly hardened portion in the support portion; Including, The light is wide-area irradiation light emitted from a first light source for curing a main portion of the curable layer occupying a wide area; and narrow-area irradiation light for an outer edge portion, which is irradiated from a second light source and cures an outer edge portion of the main portion of the curable layer, wherein the wide-area irradiation light has a relatively larger beam diameter and a relatively smaller output than the outer edge irradiation light, the main portion that is cured by the wide-area irradiation light is the strongly cured portion, the outer edge portion that is hardened by the irradiation light for the outer edge portion is a weakly hardened portion that is formed thinly on the outer periphery of the strongly hardened portion and is softer than the strongly hardened portion but has a hardness that is capable of supporting the object to be manufactured, the weakly hardened portion is formed along the outer surface of the strongly hardened portion and has a constant thickness, The weakly hardened portion has a characteristic of being more easily broken than the strongly hardened portion, and the strongly hardened portion is formed with the same hardness as the object portion. A method for producing a photocurable object of manufacture, comprising:

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