JP2015000476A - Three-dimensional molding method and three-dimensional molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional molding method capable of outputting a three-dimensional molding whose strength in a lamination direction is high at high precision.SOLUTION: Provided is a three-dimensional molding method including: a layer formation step of applying a molding material to form a molding material layer; a semi-curing step of semi-curing the molding material layer; and an addition step of adding binder grains to the semi-cured molding material layer, in which the addition step is performed to at least any one layer among a plurality of molding material layers laminated by repeating the formation step and the semi-curing step to form a three-dimensional molding.

Description

  The present invention relates to a three-dimensional modeling method and a three-dimensional modeling apparatus.

  A technique called rapid prototyping (RP) is known as a technique for modeling a three-dimensional solid object. This technology calculates the cross-sectional shape sliced thinly in the stacking direction based on the data (STL (Standard Triangulated Language) format data) that describes the surface of one 3D shape as a collection of triangles. It is a technology to form and form a three-dimensional object. In addition, as a technique for modeling a three-dimensional object, a melt deposition method (FDM: Fused Deposition Molding), an ink jet method, an ink jet binder method, a stereolithography method (SL: Stereo Lithography), a powder sintering method (SLS: Selective Laser Sintering) ) Etc. are known.

  As a three-dimensional modeling method using an inkjet method, for example, after selectively discharging a photocurable resin from an inkjet nozzle and smoothing the surface, the photocurable resin is irradiated with light and cured. There has been provided a technique for forming a three-dimensional structure by forming a layer and repeating this to form a three-dimensional structure by laminating a plurality of cured layers (see, for example, Patent Document 1). According to such a method, since a modeling material can be discharged and laminated as fine droplets, a high-definition three-dimensional model can be provided.

US Pat. No. 6,850,334

  However, according to the above-described conventional technology, since the three-dimensional structure is formed only by laminating a plurality of hardened layers, there are cases where the adhesion between the layers constituting the three-dimensional structure is not sufficient. For this reason, the strength in the stacking direction of the formed three-dimensional structure may not be sufficient. Moreover, even if it is a case where the adhesiveness between each layer which comprises a three-dimensional structure is improved by laminating the next hardened layer before a hardened layer hardens | cures completely, in the lamination direction of a three-dimensional structure In some cases, the strength was not sufficient.

  This invention is made | formed in view of the said problem, The solution subject is providing the three-dimensional modeling method and three-dimensional modeling apparatus which can output the three-dimensional modeling object with the high intensity | strength of a lamination direction accurately. .

In order to solve the above problems, the invention according to claim 1 is a three-dimensional modeling method,
A layer forming step of forming a modeling material layer by applying a modeling material;
A semi-curing step for semi-curing the modeling material layer;
An addition step of adding binder particles to the semi-cured modeling material layer,
A three-dimensional structure is formed by performing the addition step on at least one of the plurality of modeling material layers laminated by repeating the layer formation step and the semi-curing step. And

Invention of Claim 2 is the three-dimensional modeling method of Claim 1, Comprising:
The adhesion between the binder particles and the modeling material layer is greater than the adhesion between the modeling material layers.

Invention of Claim 3 is the three-dimensional modeling method of Claim 1 or 2, Comprising:
In the layer forming step, the head having a plurality of discharge nozzles in the longitudinal direction is applied by discharging droplets of the modeling material from the discharge nozzles while scanning in a direction orthogonal to the longitudinal direction. A material layer is formed.

Invention of Claim 4 is the three-dimensional modeling method as described in any one of Claim 1 to 3,
The modeling material contains a photocurable material.

Invention of Claim 5 is the three-dimensional modeling method as described in any one of Claim 1 to 4, Comprising:
Prior to the semi-curing step, the method further comprises a flattening step of flattening the surface of the modeling material layer.

Invention of Claim 6 is the three-dimensional modeling method as described in any one of Claim 1 to 5,
In the addition step, the binder particles are added to the modeling material layer by bringing the binder particles supported on a roller into contact with the modeling material layer.

Invention of Claim 7 is the three-dimensional modeling method of Claim 6, Comprising:
In the adding step, the binder particles are added to the modeling material layer while the roller is driven and rotated relative to the modeling material layer.

Invention of Claim 8 is the three-dimensional modeling method as described in any one of Claim 1-7,
In the adding step, adding the binder particles in an amount corresponding to at least one of the physical properties of the modeling material, the physical properties of the binder particles, the layer thickness of the modeling material layer, and the physical properties of the three-dimensional modeled product. Features.

Invention of Claim 9 is the three-dimensional modeling method as described in any one of Claim 1-8,
The addition step is performed on all of the plurality of modeling material layers laminated by repeating the layer forming step and the semi-curing step.

Invention of Claim 10 is the three-dimensional modeling method as described in any one of Claim 1-9,
The binder particles are surface-treated with a silane coupling agent, a titanate coupling agent or a phosphoric acid coupling agent.

The invention according to claim 11 is a three-dimensional modeling apparatus,
A discharge part for discharging a modeling material to form a modeling material layer;
A curing part for semi-curing the modeling material layer;
An additive part for adding binder particles to the modeling material layer;
And a control unit that controls the discharge unit, the curing unit, and the addition unit to form a three-dimensional structure by laminating a plurality of modeling material layers.

Invention of Claim 12 is the three-dimensional modeling apparatus of Claim 11, Comprising:
The ejection part is a head having a plurality of ejection nozzles in the longitudinal direction;
The head forms the modeling material layer by discharging droplets of the modeling material from the discharge nozzle while scanning in a direction orthogonal to the longitudinal direction.

Invention of Claim 13 is the three-dimensional modeling apparatus of Claim 11 or 12,
It further has a flattening part for flattening the surface of the modeling material layer.

Invention of Claim 14 is a three-dimensional modeling apparatus as described in any one of Claims 11-13,
The addition unit includes a roller that adds binder particles supported on a peripheral surface to the modeling material layer, and a binder particle supply source that supplies the binder particles to the roller.

The invention according to claim 15 is the three-dimensional modeling apparatus according to claim 14,
The distance between the roller and the modeling material layer is adjustable.

Invention of Claim 16 is the three-dimensional modeling apparatus of Claim 14 or 15,
The binder particle supply source supplies the binder particles to the roller such that a width of a region in which the binder particles are supported on a peripheral surface of the roller is the same as a width of the modeling material layer. Features.

The invention according to claim 17 is the three-dimensional modeling apparatus according to any one of claims 14 to 16,
The roller is composed of a conductor whose surface is insulated,
The binder particle supply source supplies the charged binder particles.

The invention according to claim 18 is the three-dimensional modeling apparatus according to any one of claims 11 to 13,
The addition part is
A photoreceptor,
A charging unit for uniformly charging the photoreceptor;
An exposure unit that performs image exposure on the photoconductor to form an electrostatic latent image; and
And a developing unit that develops the electrostatic latent image with the charged binder particles.

An invention according to claim 19 is the three-dimensional modeling apparatus according to any one of claims 14 to 18,
Each time the control unit performs the formation of the modeling material layer by the discharge unit and the semi-curing of the modeling material layer by the curing unit, the addition unit adds the binder particles.

  ADVANTAGE OF THE INVENTION According to this invention, the three-dimensional modeling method and three-dimensional modeling apparatus which can output the three-dimensional structure with the high intensity | strength of a lamination direction accurately can be provided.

It is a schematic block diagram of the three-dimensional modeling apparatus of this invention. It is a schematic block diagram which shows a part of addition part with which the three-dimensional modeling apparatus of this invention is provided. It is a schematic block diagram which shows the modification of an addition part. It is a block diagram which shows the control system of a three-dimensional modeling apparatus. It is a figure explaining the relationship between the hardening degree of a modeling material layer, and adhesiveness. It is a figure explaining the state of modeling material and an additive in each process.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  A three-dimensional modeling apparatus 100 of the present invention that forms a three-dimensional modeled object will be described below with reference to FIGS. FIG. 1 is a schematic configuration diagram illustrating the three-dimensional modeling apparatus 100, FIG. 2 is a schematic configuration diagram illustrating a part of the addition unit 4 included in the three-dimensional modeling apparatus 100, and FIG. FIG. 4 is a schematic configuration diagram illustrating a modification, and FIG. 4 is a block diagram illustrating a control system of the three-dimensional modeling apparatus 100.

  The three-dimensional modeling apparatus 100 of the present invention includes an inkjet head (discharge unit) 1 that discharges and applies a modeling material to form a modeling material layer, a flattening unit 2 that planarizes the surface of the modeling material layer, and a modeling material layer. Semi-curing curing section 3, addition section 4 for adding binder particles 41 to the modeling material layer, moving mechanism 5 for moving these sections as a unit, modeling stage 6 for supporting the formed three-dimensional model, and these sections The control part 7 etc. which control are comprised.

  As shown in FIG. 1, the inkjet head 1, the flattening unit 2, the curing unit 3, and the adding unit 4 are provided adjacent to each other in this order, and these are integrated as a unit on the modeling stage 6 by the moving mechanism 5. Move to. When the inkjet head 1 is moved in the direction A in FIG. 1 by the moving mechanism 5, the inkjet head 1 discharges the modeling material.

The inkjet head 1 has a plurality of discharge nozzles in the longitudinal direction, and selectively discharges droplets of the modeling material from the plurality of discharge nozzles while scanning in a direction orthogonal to the longitudinal direction by the moving mechanism 5. A modeling material layer is formed in a desired region on the modeling stage 6.
As such an inkjet head 1, a conventionally known inkjet head for image formation is used.

The inkjet head 1 stores a modeling material. The modeling material is a material for forming a three-dimensional structure, and is stored in the inkjet head 1 in a dischargeable state. The modeling material is discharged onto the modeling stage 6 by the inkjet head 1 to form a modeling material layer. Furthermore, the modeling material layer is semi-cured by being subjected to any curing treatment such as light irradiation, cooling, or heating. Here, the semi-curing is a state in which the modeling material layer formed by applying the modeling material is cured so as to have a viscosity that can maintain the shape as a layer and can retain the added binder particles 41. Specifically, when the modeling material is a photocurable material or a thermosetting material, the reaction rate is 20% or more and less than 90%. When the modeling material includes a phase change material and is cured at room temperature, it corresponds to semi-curing even if the reaction rate is less than 20%.
The semi-cured modeling material layer is further cured by being subjected to a curing process.

As such a modeling material, for example, a photocurable material that cures when irradiated with light, a thermosetting material, a thermoplastic material, or the like is used.
Examples of the photocurable material include an ultraviolet curable resin, a radical polymerization type ultraviolet curable resin such as acrylic acid ester or vinyl ether, a monomer or an oligomer such as epoxy or oxetane, and a reaction initiator depending on the resin. A cationic polymerization ultraviolet curable resin that is used in combination with acetophenone, benzophenone, or the like can be used.
Examples of the thermosetting material include a thermosetting resin, and a combination of a radical polymerization resin and a thermal radical generator can be used.
As the thermoplastic material, a conventionally known thermoplastic resin can be used. When a thermoplastic material is used as the modeling material, the thermoplastic material is discharged from the inkjet head 1 while being heated and softened.

Further, as the modeling material, it is also possible to use a phase transition material whose hardness reversibly changes with the transition temperature Tm as a boundary. When the modeling material is a phase transition material that is softened at a transition temperature Tm or higher, the phase transition material is heated from the transition temperature Tm or higher and discharged from the inkjet head 1 in a softened state.
Moreover, it is preferable that a phase change material is used as a modeling material in the state contained in the photocurable material. In this case, the modeling material can be cured by controlling the temperature, and the modeling material can be cured by irradiating light. Therefore, it is easy to adjust the semi-cured state or the cured state of the modeling material. .

  In addition, the modeling material is discharged from the inkjet head 1, but the modeling material is supplied from another ejection nozzle of the inkjet head 1 or an inkjet head (not shown) different from the inkjet head 1 together with the modeling material. The supporting material to be supported may be discharged. The support material is provided on the lower layer side of the modeling material layer, for example, when the modeling target has an overhanging part, and supports the overhanging part until the formation of the three-dimensional modeling object is completed. The support material may be provided adjacent to the modeling material layer to protect the formed three-dimensional modeled object. Such a support material is removed after the formation of the three-dimensional structure is completed.

  The flattening unit 2 contacts the leveling roller 21 with the surface of the modeling material layer formed by the inkjet head 1 to planarize the unevenness of the surface of the modeling material layer so that the cured modeling material layer has a desired layer thickness. To flatten. By flattening the modeling material layer surface by the flattening unit 2, it is possible to accurately model a three-dimensional modeled object. The leveling roller 2 is configured to be rotationally driven. The rotation direction of the leveling roller 21 at the position in contact with the modeling material layer is substantially the same direction (direction B shown in FIG. 1) as the relative movement direction (direction A shown in FIG. 1) of the flattening unit 2 with respect to the modeling material layer. The rotation speed of the leveling roller 21 is the same as the relative movement speed of the leveling roller 21 and the modeling material layer. Thus, the surface of the modeling material layer can be efficiently flattened while leveling unnecessary portions of the modeling material on the modeling stage 6 and scraping off the surface of the roller 21. The modeling material adhering to the surface of the leveling roller 21 is scraped off by the blade 22 provided in the vicinity of the leveling roller 21 and collected in the bath 23. The modeling material collected in the bus 23 may be supplied to the inkjet head 1 and reused, or may be transported to a waste tank.

  The curing unit 3 performs a curing process on the modeling material layer formed on the modeling stage 6 so as to be semi-cured.

The configuration of the curing unit 3 varies depending on the properties of the modeling material.
In the example shown in FIG. 1, since the modeling material is an ultraviolet curable material, an ultraviolet light source is used as the curing unit 3. Specifically, as the curing unit 3, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, an ultraviolet LED, or the like can be used.

In addition, when the modeling material is a thermosetting material, a heating unit that generates heat from a resistance heating element or the like is used as the curing unit 3.
In addition, when the modeling material is a thermoplastic material, a cooling means is used as the curing unit 3, but natural cooling may be used.
Furthermore, when the modeling material is a phase transition material that softens at a transition temperature Tm or higher, a cooling unit that cools the phase transition material to a temperature lower than the transition temperature Tm is used as the curing unit 3, but natural cooling may be used.

  The addition unit 4 adds binder particles 41 to the modeling material layer semi-cured by the curing unit 3. Since the binder particles 41 are added to the semi-cured modeling material layer, the binder particles 41 are adhered and held on the modeling material layer, and the binder particles 41 can be efficiently added. Here, the binder particle is a particle that is chemically bonded to the modeling material layer or has an uneven surface and exhibits an anchor effect on the modeling material layer, and is bonded between the modeling material layers. It enhances sex.

The addition amount of the binder particles 41 added to the modeling material layer by the adding unit 4 depends on the physical properties of the modeling material, the layer thickness of the modeling material layer, the physical properties of the three-dimensional modeling object, the physical properties of the binder particles 41, and the like. 7 is set. Specifically, when the adhesion between the modeling material layers is low, or when the strength in the stacking direction of the three-dimensional model is improved, the amount of the binder particles 41 added is increased. Further, when the layer thickness of the modeling material layer is large, that is, when the stacking pitch is large, the stress is easily concentrated between the layers of the formed three-dimensional modeled object, so that the amount of the binder particles 41 added is increased. Thus, when improving the adhesiveness between modeling material layers, the addition amount of the binder particle 41 is increased. The physical properties of the binder particles 41 include the material, particle size, shape, mass, and the like of the binder particles 41, and the adhesion between the modeling material layers when the binder particles 41 are added varies accordingly.
In addition, the addition amount of the binder particles 41 by the addition unit 4 may not be set according to each of the above conditions, but may be a preset amount.

  The addition unit 4 includes an addition roller 42 that adds the binder particles 41 supported on the peripheral surface to the modeling material layer, a binder particle supply source 43 that supplies the binder particles 41 to the addition roller 42, and the like.

  The addition roller 42 is made of, for example, a metal such as stainless steel or a resin such as acrylic resin. When the surface layer of the addition roller 42 is made of a resin, particulate matter such as silica may be dispersed in the surface layer to improve wear resistance.

  A plurality of binder particles 41 are carried on the surface of the addition roller 42. The addition roller 42 moves relative to the modeling material layer in a state where the supported binder particles 41 are in contact with the modeling material layer, and rotates following the relative movement with respect to the modeling material layer. Thereby, the binder particles 41 can be added to the modeling material layer surface without scratching the modeling material layer surface flattened by the planarization unit 2.

Further, the distance between the addition roller 42 and the modeling material layer in the vertical direction is configured to be adjustable, the surface of the addition roller 42 does not directly contact the modeling material layer, and the binder particles 41 contact the modeling material layer. It is preferable to adjust to such a range.
For example, as shown in FIG. 2, when the stacking pitch P is 15 to 30 μm and the particle size of the binder particles 41 is 1 to 10 μm, the distance D between the addition roller 42 and the modeling material layer is preferably 0 to 5 μm. The positioning of the addition roller 42 with respect to the modeling material layer can be performed by driving the nanometer order with a linear motor or the like, for example.
Since the position of the addition roller 42 is controlled in this way, the addition roller 42 comes close to only the uppermost layer among the plurality of modeling material layers stacked on the modeling stage 6 and the binder particles 41 are brought into contact with each other. Therefore, the binder particles 41 can be selectively added only to the top modeling material layer.

  The binder particle supply source 43 supplies the binder particles 41 stored therein to the surface of the addition roller 42, whereby the binder particles 41 are supported on the surface of the addition roller 42. The binder particle supply source 43 supplies the binder particles 41 to the addition roller 42 so that the width of the area where the binder particles 41 are carried on the peripheral surface of the addition roller 42 is the same as the width of the modeling material layer. Is preferred.

As the binder particles 41 stored in the binder particle supply source 43, particles having greater adhesion between the binder particles 41 and the modeling material layer than the adhesion between the modeling material layers are used.
As the binder particles 41, for example, inorganic particles or organic particles subjected to a coupling treatment are used. Examples of the inorganic particles include various metal oxides such as silica, alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, and bismuth oxide. These can be used alone or in combination. Moreover, as an organic particle, what has the surface structure which can react with a coupling treating agent is used, for example, specifically, a silicone resin particle etc. are mentioned.

  The binder particles 41 are preferably surface-treated with a coupling treatment agent. Thereby, the adhesiveness of the binder particle 41 and the modeling material layer can be improved. Examples of the coupling treatment used include a silane coupling agent, a titanate coupling agent, or a phosphoric acid coupling agent, and a functional group capable of binding to a compound contained in a modeling material is imparted to the particles. What can be done is preferred. For example, when an acrylic ester is used for the modeling material, it is preferable that a vinyl group is imparted to the surface of the binder particle 41 by a coupling process.

Moreover, in order to prevent that the binder particle 41 touches the area | region where the binder particle 41 does not need to be added on a modeling material layer, it is preferable that it is a shape close | similar to a spherical shape. For example, the particle size of the binder particles 41 is preferably 1 to 10 μm with respect to the stacking pitch of 15 to 30 μm. Thus, the particle size of the binder particles 41 is preferably smaller than the stacking pitch. In order to make the addition amount of the binder particles 41 to the modeling material layer and the amount of the binder particles 41 supported by the addition roller 42 in contact with the modeling material layer, these particles have a sharp particle size distribution. It is preferable to have.
The binder particles 41 may be non-spherical particles such as needles, but in that case, the major axis of the binder particles 41 is preferably smaller than the stacking pitch.

  As shown in FIG. 1, when the binder particle supply source 43 is configured to contact and adhere the binder particles 41 to the surface of the addition roller 42, the surface of the addition roller 42 is more than the binder particle supply source 43. A regulating plate (not shown) is provided on the downstream side in the rotational direction and on the upstream side in the rotational direction from the position close to the modeling material layer. The restricting plate abuts the binder particles 41 carried on the addition roller 42 at the tip thereof, and makes the carrying amount of the binder particles 41 carried on the addition roller 42 constant in the surface direction.

  In addition, the addition part 4 is comprised so that the addition roller 42 may be comprised with the electroconductive rotary body in which the insulating layer was provided in the surface, and the binder particle supply source 43 supplies the charged binder particle 41. Also good. Thereby, a voltage is applied between the binder particle supply source 43 and the addition roller 42, and the charged binder particles 41 are caused to fly on the principle of electrostatic coating and are carried on the surface of the addition roller 42. May be. Thereby, the binder particles 41 can be uniformly supported on the peripheral surface of the addition roller 42.

  Further, as shown in FIG. 3, the addition unit 4 may have a configuration using the principle of electrophotographic technology. That is, the addition unit 4 includes a photoconductor 44, a charging unit 45 that uniformly charges the photoconductor 44, an exposure unit 46 that performs image exposure on the photoconductor 44 to form an electrostatic latent image, and charged binder particles. 41 includes a developing unit 47 for developing the electrostatic latent image. The adding unit 4 charges the photoconductor 44 by the charging unit 45, and performs image exposure on the photoconductor 44 by the exposure unit 46 to form an electrostatic latent image on the surface of the photoconductor 44. By applying a voltage in between, the binder particles 41 frictionally charged by the developing unit 47 fly and adhere to the surface of the photoreceptor 44. As a result, the binder particles 41 can be selectively supported on the photoconductor 44, and the modeling material is brought into contact with the modeling material layer by bringing the photoconductor 44 close to the modeling material layer. Binder particles 41 can be selectively added to the layer.

  The addition unit 4 may further include a cleaning unit (not shown) that removes the binder particles 41 remaining on the surface of the addition roller 42 and the modeling material attached to the surface of the addition roller 42 by contact with the modeling material layer. . The cleaning unit is preferably provided in the vicinity of the addition roller 42 on the downstream side in the rotational direction from the position close to the modeling material layer and on the upstream side in the rotational direction from the binder particle supply source 43. As a cleaning part, scrapers, such as a metal plate and a rubber plate, may be sufficient, for example, and it may be a member comprised by the brush shape and scraping off the deposit | attachment on the surface of the addition roller 42. Deposits removed from the surface of the addition roller 42 by the cleaning unit are transported to a waste tank.

In this manner, the N + 1-th modeling material layer is again formed by the inkjet head 1 on the N-th modeling material layer (N represents an integer of 1 or more) to which the binder particles 41 have been added by the addition unit 4. By forming, the adhesion between the Nth modeling material layer and the (N + 1) th modeling material layer can be improved.
Here, FIG. 5 is a diagram schematically showing the relationship between the degree of cure of the modeling material layer and the adhesion of the modeling material layer, and the alternate long and short dash line a indicates the case where the binder particles 41 are not added. The solid line b shows the case where the binder particles 41 are added.
As shown in FIG. 5, as the degree of cure of the modeling material layer increases, the adhesion of the modeling material layer decreases, but by adding the binder particles 41, the modeling material layer regardless of the degree of curing. The adhesion is improved.

  The moving mechanism 5 moves the inkjet head 1, the flattening unit 2, the curing unit 3, and the adding unit 4 together on the modeling stage 6 in the horizontal direction. The moving mechanism 5 may be configured to move each part in the vertical direction.

  There is no particular limitation on the path for scanning each part of the inkjet head 1 and the like on the modeling stage 6 by the moving mechanism 5. For example, first, the inkjet head 1 or the like is scanned from one edge on the modeling stage 6 to the other edge in the main scanning direction while forming a coating film, flattening, semi-curing, and adding the binder particles 41, respectively. To do. Next, the formation of the coating film, planarization, semi-curing, and addition of the binder particles 41 are temporarily stopped, and the inkjet head 1 and the like are scanned by the nozzle pitch in the sub-scanning direction. Next, the inkjet head 1 and the like are moved from the other edge on the modeling stage 6 in the main scanning direction while forming a coating film on the predetermined region, flattening, semi-curing, and adding the binder particles 41 again. Scan to one edge. By repeating these steps, the entire modeling stage 6 can be scanned to form a modeling material layer.

  Further, in order to improve the denseness of the three-dimensional structure in the sub-scanning direction, when the inkjet head 1 or the like is scanned in the sub-scanning direction, it is scanned by a distance corresponding to 1/2 or 1/4 of the nozzle pitch. Anyway. For example, when an ink jet head of 75 dpi is used and scanning is performed by a distance corresponding to 1/4 of the nozzle pitch in the sub-scanning direction, a 300 dpi layer can be formed by two reciprocations and four scans in the main scanning direction. . When the inkjet head 1 or the like is scanned in this way, the modeling material layer is semi-cured by the curing unit 3 and the binder particles 41 are added by the adding unit 4 only during the fourth scanning in the main scanning direction. May be. Thereby, while being able to perform ultraviolet irradiation equally with respect to each of the modeling material layer formed by the scanning in the 1st-4th main scanning direction, the binder particle | grains 41 can be added equally and subscanning can be performed. The unevenness of the denseness of the three-dimensional structure in the direction can be reduced.

A three-dimensional structure is formed on the upper surface of the modeling stage 6 by the inkjet head 1, the flattening unit 2, the curing unit 3, and the adding unit 4, and supports the three-dimensional modeled object. The modeling stage 6 is configured to be movable in the vertical direction. After the Nth modeling material layer is formed on the modeling stage 6, the modeling stage 6 is lowered downward in the vertical direction by a distance corresponding to the stacking pitch.
The modeling stage 6 may be configured to be movable in the horizontal direction with respect to the inkjet head 1, the flattening unit 2, the curing unit 3, and the addition unit 4.

The control part 7 controls each part of the three-dimensional modeling apparatus 100 as shown in FIG. The control unit 7 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory) (not shown), and performs various operations according to various processing programs for the 3D modeling apparatus 100.
Specifically, the control unit 7 controls the inkjet head 1, the curing unit 3, and the addition unit 4 to form a three-dimensional structure by laminating a plurality of modeling material layers.

  The control unit 7 receives 3D data (for example, CAD data and design data) of the modeling target from a 3D data input unit (not shown). The CAD data and the design data may include not only the shape data of the modeling target but also color image information (color information) on a part or the entire surface and inside. The 3D data may be acquired directly from a computer that designs the modeling target, or may be acquired from a server or the like that manages / stores 3D data.

  Based on the input 3D data, the control unit 7 reconstructs data for each layer (hereinafter referred to as slice data) for modeling a modeling material in three dimensions by a calculation unit such as a CPU. Moreover, the control part 7 controls the operation | movement of the three-dimensional modeling apparatus 100 whole during modeling operation. For example, control information for discharging the modeling material to a desired region on the modeling stage 6 is transmitted to the moving mechanism 5, and slice data is transmitted to the inkjet head 1. That is, the control unit 7 controls the inkjet head 1 and the moving mechanism 5 in synchronization.

Further, for example, the control unit 7 transmits control information indicating conditions for the curing unit 3 to semi-cure the modeling material layer to the curing unit 3. In the example shown in FIG. 1, since an ultraviolet light source is used as the curing unit 3, the control unit 7 transmits information such as illuminance and irradiation time necessary for semi-curing the modeling material by the ultraviolet light source.
Further, the control unit 7 sets the addition amount for adding the binder particles 41 to the modeling material layer by the addition unit 4 according to the various conditions described above, and transmits this to the addition unit 4. Further, when the addition unit 4 has a configuration using an electrophotographic technique as shown in FIG. 3, the control unit 7 sends control information indicating an electrostatic latent image formed on the photoreceptor 44 to the addition unit 4. Send.

  The control unit 7 and the 3D data input unit may be configured as hardware, or may be configured as a control program that functions as the control unit 7 and the 3D data input unit. Or it is good also as a structure operated with the apparatus which controls the said 3D modeling apparatus 100 concerned.

Formation of a three-dimensional structure by the three-dimensional structure forming apparatus 100 configured as described above will be described with reference to FIG. FIG. 6 is a diagram illustrating the state of the Nth layer and the (N + 1) th layer in forming a three-dimensional structure.
First, the control unit 7 controls each unit based on the slice data, and scans the inkjet head 1, the flattening unit 2, the curing unit 3, and the addition unit 4 as a unit on the modeling stage 6 by the moving mechanism 5. Formation of the modeling material layer L11 by 1 (see FIG. 6A), planarization of the modeling material layer L11 by the flattening unit 2, semi-curing of the modeling material layer L11 by the curing unit 3 (see FIG. 6B), The binder particles 41 are added to the modeling material layer L12 in a semi-cured state by the addition unit 4 (see FIG. 6C). Thus, a semi-cured modeling material layer L12 to which the binder particles 41 are added is formed in a predetermined region on the modeling stage 6. In the example shown in FIG. 6, surface-treated particles are used as the binder particles 41.

  Subsequently, the control unit 7 moves the respective parts upward by the stacking pitch by the moving mechanism 5, and then scans the respective parts on the modeling stage 6 again based on the slice data, while the semi-cured modeling material A second modeling material layer L21 is formed on the layer L12 (see FIG. 6D), the modeling material layer L21 is flattened, and the modeling material layer L21 is semi-cured (see FIG. 6E). The binder particles 41 are added to the modeling material layer L21 in a semi-cured state. By semi-curing the modeling material layer L21, the semi-cured modeling material layer L12 provided on the lower layer side is cured to form a cured modeling material layer L13. Thereby, the binder particles 41 added to the first modeling material layer L13 strongly adhere to the modeling material layer L13 and strongly adhere to the semi-cured modeling material layer L22. Further, when the second modeling material layer L21 is formed, since the lower modeling material layer L12 is in a semi-cured state, the first modeling material layer L12 and the second modeling material layer L21 are strongly bonded. To do. Thus, the control unit 7 forms the modeling material layer by the inkjet head 1, planarizes the modeling material layer by the flattening unit, semi-cures the modeling material layer by the curing unit 3, and forms the binder particles 41 by the addition unit 4. By repeating the addition, each modeling material layer after the second layer is formed, and a three-dimensional modeling of a desired shape having high strength in the stacking direction is formed.

In addition, whenever the control part 7 performs the formation of the modeling material layer by the inkjet head 1 and the semi-curing of the modeling material layer by the curing part 3 a plurality of times, the addition part 4 adds the binder particles 41 to the modeling material layer. It is also good. In other words, the control unit 7 may add the binder particles 41 only between any layers in the plurality of modeling material layers constituting the three-dimensional structure, or the binder particles 41 only between any layers. It is good also as what does not add.
By adding the binder particles 41 only between any one of the plurality of modeling material layers constituting the three-dimensional structure, the binder particles 41 are added only to necessary portions in the three-dimensional structure, for example, low-strength portions. Thus, the three-dimensional structure can be locally reinforced using the minimum necessary binder particles 41.
In addition, by not adding the binder particles 41 only between any one of the plurality of modeling material layers constituting the three-dimensional structure, it is possible to actively provide a portion having a low strength in the stacking direction of the three-dimensional structure. It is also possible to form a three-dimensional structure separable in the stacking direction.
Further, the controller 7 adds the binder particles 41 between all the layers of the modeling material layer constituting the three-dimensional structure, and the binder only between any one of the modeling material layers constituting the three-dimensional structure. You may be comprised so that the aspect which adds the particle | grains 41 may be selected.

In the three-dimensional modeling apparatus 100 described above, the inkjet head 1 is provided as a discharge unit, but another discharge unit may be provided instead of the inkjet head 1.
Further, in the above-described three-dimensional modeling apparatus 100, the flattening unit 2 is provided, but the flattening unit 2 may not be provided.
In addition, in the above-described three-dimensional modeling apparatus 100, the addition unit 4 may not be configured to include the addition roller 42 and the binder particle supply source 43. For example, the binder particles 41 are sprayed on the modeling material layer. You may comprise so that it can apply | coat and add.

  In the 3D modeling apparatus 100 described above, the inkjet head 1, the flattening unit 2, the curing unit 3, and the addition unit 4 are moved together by the moving mechanism 5, but these units are provided separately. May be. That is, the moving mechanism 5 may be configured to move only the inkjet head 1, and the flattening unit 2, the curing unit 3, and the adding unit 4 may be moved by different moving mechanisms.

  Subsequently, the three-dimensional modeling method of the present invention will be described.

  In the example of the three-dimensional modeling method described below, a method of forming a three-dimensional modeled object using the above-described three-dimensional modeling apparatus 100 will be described with reference to FIG. The 3D modeling method of the present invention may be performed without using the 3D modeling apparatus 100.

  First, on the modeling stage 6, while the inkjet head 1 having a plurality of discharge nozzles in the longitudinal direction is scanned in a direction perpendicular to the longitudinal direction by the moving mechanism 5, droplets of the modeling material are discharged from the plurality of discharge nozzles. Then, a modeling material layer is formed in a predetermined region on the modeling stage 6 (layer forming step). It is assumed that the modeling material contains an ultraviolet curable resin.

  Next, the surface of the modeling material layer is flattened by bringing the leveling roller 21 of the flattening unit 2 into contact with the formed modeling material layer and rotating the leveling roller 21 on the modeling material layer. (Flattening step).

  Next, the flattened modeling material layer is irradiated with ultraviolet rays by the curing unit 3, and the modeling material layer is semi-cured (semi-curing step). The illuminance and irradiation time of ultraviolet irradiation by the curing unit 3 are set according to the modeling material so that the modeling material layer can be semi-cured.

Next, the addition roller 42 is moved relative to the modeling material layer in a state where the binder particles 41 supported by the addition roller 42 are in contact with the modeling material layer with respect to the semi-cured modeling material layer, and then added. The binder particles 41 are added to the modeling material layer while the roller 42 is driven to rotate relative to the modeling material layer (addition process). In addition, as the binder particles 41, those having greater adhesion between the binder particles 41 and the modeling material layer than the adhesion between the modeling material layers are used. Such binder particles 41 are preferably surface-treated with a silane coupling agent, a titanate coupling agent, or a phosphoric acid coupling agent.
Moreover, it is preferable to set the addition amount of the binder particle 41 in an addition process according to the physical property of modeling material, the layer thickness of a modeling material layer, the physical property of a three-dimensional molded item, the physical property of the binder particle 41, etc.

And the above-mentioned layer formation process, a planarization process, a semi-hardening process, and an addition process are again performed on the modeling material layer of the semi-hardened state which added the binder particle | grains 41, and the next modeling material layer is formed. By the semi-curing process performed here, the modeling material layer formed by the layer forming process is semi-cured and the modeling material layer on the lower layer side is cured.
As described above, by repeatedly performing the layer forming step, the planarization step, the semi-curing step, and the addition step, a plurality of modeling material layers can be stacked to form a three-dimensional structure.

In the above three-dimensional modeling method, the modeling material contains the ultraviolet curable resin, but the ultraviolet curable resin may not be contained. In this case, the method of semi-curing the modeling material layer in the semi-curing process is appropriately set according to the material used for the modeling material, not ultraviolet irradiation.
In the three-dimensional modeling method described above, the planarization step is performed after the layer formation step, but the planarization step may not be performed.
Moreover, in the above-described three-dimensional modeling method, the addition step is performed every time the layer formation step, the planarization step, and the semi-curing step are performed. It is good also as what performs an addition process as needed.

  As described above, according to the three-dimensional forming apparatus and the three-dimensional forming method of the present embodiment, the modeling material is discharged to form the modeling material layer, the modeling material layer is semi-cured, and the binder particles are formed on the semi-cured modeling material layer. Since 41 is added, the binder particles 41 are interposed between the modeling material layers, and a three-dimensional structure having high strength in the stacking direction can be formed with high accuracy. Moreover, since the next modeling material layer is laminated | stacked on the modeling material layer of the semi-hardened state, the adhesiveness of modeling material layers can be improved.

  The inkjet head 1 is a head having a plurality of discharge nozzles in the longitudinal direction, and forms a modeling material layer by discharging droplets of the modeling material from the discharge nozzles while scanning in a direction orthogonal to the longitudinal direction. Therefore, it is possible to divert the conventionally known mechanism of an inkjet head for image formation. Thereby, a three-dimensional structure can be formed at low cost.

  Moreover, since the surface of the modeling material layer is flattened, the surface of the modeling material layer formed by the inkjet head 1 can be flattened, and each modeling material layer can be laminated with high accuracy. Thereby, a three-dimensional structure can be formed with higher accuracy.

  Further, the addition unit 4 supplies the binder particles 41 to the addition roller 42 from the binder particle supply source 43, and the binder particles 41 supported on the peripheral surface of the addition roller 42 are brought into contact with the modeling material layer to be bonded to the modeling material layer. Since the particles 41 are added, the binder particles 41 can be added only to the uppermost layer of the modeling material layers that have already been laminated. For this reason, the usage-amount of the binder particle | grains 41 can be reduced and a three-dimensional structure can be formed at low cost.

  Further, since the binder particles 41 are added to the modeling material layer while the addition roller 42 is driven to rotate relative to the modeling material layer, the binder particles 41 are more reliably added without damaging the modeling material layer. be able to.

  Moreover, since the addition amount of the binder particle 41 is set according to the physical property of the modeling material, the physical property of the binder particle 41, the layer thickness of the modeling material layer, the physical property of the three-dimensional modeled object, etc., the usage amount of the binder particle 41 is reduced. The three-dimensional structure can be formed at a low cost because it can be minimized.

  Moreover, since the distance between the addition roller 42 and the modeling material layer can be adjusted, the arrangement of the binder particles 41 between the layers can be adjusted according to the stacking pitch and the particle size of the binder particles 41, Interlayer adhesion can be improved more reliably.

  In addition, the binder particle supply source 43 has the binder particles on the addition roller 42 so that the width of the region where the binder particles 41 are carried on the peripheral surface of the addition roller 42 is the same as the width of the modeling material layer to be formed. Since 41 is supplied, the binder particles 41 can be added only to the necessary portions of the addition roller 42. Thereby, the usage-amount of the binder particle | grains 41 can be reduced and a three-dimensional molded item can be formed at low cost.

  Further, when the addition roller 42 is composed of a conductor whose surface is insulated, and the binder particle supply source 43 supplies the charged binder particles 41, the binder is uniformly distributed on the peripheral surface of the addition roller 42. The particles 41 can be supported.

  The addition unit 4 is charged with a photosensitive member 44, a charging unit 45 that uniformly charges the photosensitive member 44, and an exposure unit 46 that forms an electrostatic latent image that performs image exposure on the photosensitive member 44. In addition, the binder particles 41 can be selectively added to the modeling material layer in the case where the binder particles 41 include the developing unit 47 that develops the electrostatic latent image. Thereby, for example, when forming a three-dimensional structure using a support material, the binder particles 41 are selectively added only on the modeling material without adding the binder particles 41 to the support material. The amount of binder particles 41 used can be reduced. Thereby, a three-dimensional structure can be formed at low cost.

  Moreover, when adding the binder particle | grains 41 with respect to all the modeling material layers formed, the binder particle | grains 41 can be interposed between the layers of each modeling material layer which comprises a three-dimensional molded item, and a lamination direction A three-dimensional structure with high strength can be formed throughout.

  In addition, since the binder particles 41 are surface-treated with a silane coupling agent, a titanate coupling agent, or a phosphoric acid coupling agent, the binder particles 41 can be reliably adhered to the modeling material layer in the stacking direction. A three-dimensional structure with higher strength can be formed.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to a following example.

[Example 1]
<< Production of three-dimensional structure 1-1 >>
On the modeling stage, urethane acrylate, which is a radical polymerization type ultraviolet curable resin, was discharged as a modeling material from the inkjet head to form a modeling material layer. The formed modeling material layer was semi-cured by irradiating ultraviolet rays for a predetermined time at an illuminance of about 100 mW / cm ² using a high-pressure mercury lamp. An addition roller carrying silica particles having a particle diameter of 1 to 10 μm as binder particles was driven to rotate relative to the semi-cured modeling material layer, and the silica particles were added to the modeling material layer. Further, silica particles that had been surface-treated with a silane coupling agent having a vinyl group in advance were used. Further, the addition amount of silica particles was set to 10 mass% with respect to the modeling material discharged on the modeling stage. After adding silica particles to the modeling material layer, the modeling stage was lowered downward in the vertical direction by the stacking pitch. The operation as described above was repeated to form the second and subsequent modeling material layers, and a three-dimensional modeled object 1-1 was produced.

<< Production of three-dimensional structure 1-2 >>
In the production of the above-described three-dimensional structure 1-1, a three-dimensional structure 1-2 was produced in the same manner except that the silica particles were not added to the semi-cured modeling material layer.

<< Production of three-dimensional structure 1-3 >>
In the production of the above-described three-dimensional structure 1-1, the urethane acrylate as the modeling material was previously discharged from the inkjet head containing silica particles as the binder particles, but ink clogging occurred in the discharge nozzle, The modeling material layer could not be formed.

<< Evaluation of three-dimensional structure 1-1, 1-2 >>
The following evaluation was performed about the three-dimensional structure 1-1 and 1-2 produced as mentioned above. The evaluation results are shown in Table 1.

(1) Modeling material discharge possibility The injection state of the modeling material from the discharge nozzle of the inkjet head was confirmed by visual observation and evaluated according to the following criteria.
○: No nozzle shortage occurs even after 30 minutes of continuous emission.
X: Nozzle is generated in several or more discharge nozzles by continuous emission for 30 minutes.

(2) Tensile strength measurement The tensile strength in the lamination direction of the produced three-dimensional structure was measured according to JIS K-7162 and evaluated according to the following criteria.
A: 50 MPa or more O: 10-50 MPa
X: 0 to 10 MPa

(3) Measurement of elongation at break The elongation at break in the stacking direction of the produced three-dimensional structure was measured according to JIS K-7162 and evaluated according to the following criteria.
◎: 10% or more ○: 1-10%
X: 0 to 1%

When binder particles were included in the modeling material, the modeling material layer could not be formed due to defective ejection, and a three-dimensional modeled object could not be formed with high accuracy.
On the other hand, as in the present invention, after semi-curing a modeling material layer made of a modeling material, when a layer was formed by adding binder particles, a three-dimensional modeled object could be formed. . In addition, by forming a three-dimensional structure by laminating a modeling material layer to which binder particles are added, compared to a three-dimensional structure formed by laminating a modeling material layer to which no binder particles are added, The tensile strength in the laminating direction could be improved.
Therefore, according to the three-dimensional modeling method of the present invention, it can be said that a three-dimensional modeled object having high adhesion between layers can be output with high accuracy.

[Example 2]
In the production of the three-dimensional structure 1-1 of Example 1, a three-dimensional structure was prepared in the same manner except that the binder particles were added to the modeling material layer by electrophotography using a photoreceptor as an addition roller. . That is, the photosensitive member was uniformly charged by the charging unit, an electrostatic latent image was formed on the photosensitive member by the exposure unit, and the silica particles charged by the developing unit were attached to the photosensitive member. By bringing the photoconductor close to the modeling material layer and bringing the silica particles into contact with the modeling material layer, the silica particles could be added to the region corresponding to the electrostatic latent image on the modeling material layer.
Therefore, it was confirmed that by adding binder particles using electrophotographic technology, binder particles can be selectively added to the modeling material layer, and a three-dimensional structure having high strength in the stacking direction can be formed.

1 Inkjet head (ejection unit)
DESCRIPTION OF SYMBOLS 2 Flattening part 3 Curing part 4 Addition part 5 Movement mechanism 6 Modeling stage 7 Control part 21 Leveling roller 22 Blade 23 Bath 41 Binder particle 42 Addition roller 43 Binder particle supply source 44 Photoconductor 45 Charging part 46 Exposure part 47 Development part 100 Three-dimensional modeling apparatus L11-L13, L21, L22 Modeling material layer

Claims (19)

A layer forming step of forming a modeling material layer by applying a modeling material;
A semi-curing step for semi-curing the modeling material layer;
An addition step of adding binder particles to the semi-cured modeling material layer,
A three-dimensional structure is formed by performing the addition step on at least one of the plurality of modeling material layers laminated by repeating the layer formation step and the semi-curing step. 3D modeling method.   The three-dimensional modeling method according to claim 1, wherein the adhesion between the binder particles and the modeling material layer is greater than the adhesion between the modeling material layers.   In the layer forming step, the head having a plurality of discharge nozzles in the longitudinal direction is applied by discharging droplets of the modeling material from the discharge nozzles while scanning in a direction orthogonal to the longitudinal direction. The three-dimensional modeling method according to claim 1, wherein a material layer is formed.   The said modeling material contains a photocurable material, The three-dimensional modeling method as described in any one of Claim 1 to 3 characterized by the above-mentioned.   5. The three-dimensional modeling method according to claim 1, further comprising a flattening step of flattening a surface of the modeling material layer before the semi-curing step.   The said addition process WHEREIN: The said binder particle | grain is added to the said modeling material layer by making the said binder particle carry | supported by the roller contact the said modeling material layer, The any one of Claim 1 to 5 characterized by the above-mentioned. The three-dimensional modeling method described in 1.   The three-dimensional modeling method according to claim 6, wherein, in the adding step, the binder particles are added to the modeling material layer while the roller is driven to rotate relative to the modeling material layer.   In the adding step, adding the binder particles in an amount corresponding to at least one of the physical properties of the modeling material, the physical properties of the binder particles, the layer thickness of the modeling material layer, and the physical properties of the three-dimensional modeled product. The three-dimensional modeling method according to claim 1, wherein the three-dimensional modeling method is characterized.   The said addition process is performed with respect to all the several said modeling material layers laminated | stacked by repeating the said layer formation process and the said semi-hardening process, The Claim 1 characterized by the above-mentioned. Three-dimensional modeling method.   The three-dimensional modeling method according to any one of claims 1 to 9, wherein the binder particles are surface-treated with a silane coupling agent, a titanate coupling agent, or a phosphoric acid coupling agent. A discharge part for discharging a modeling material to form a modeling material layer;
A curing part for semi-curing the modeling material layer;
An additive part for adding binder particles to the modeling material layer;
A three-dimensional modeling apparatus comprising: a control unit that controls the discharge unit, the curing unit, and the addition unit to form a three-dimensional structure by laminating a plurality of modeling material layers. The ejection part is a head having a plurality of ejection nozzles in the longitudinal direction;
The tertiary according to claim 11, wherein the head forms the modeling material layer by discharging droplets of the modeling material from the discharge nozzle while scanning in a direction orthogonal to the longitudinal direction. Original modeling device.   The three-dimensional modeling apparatus according to claim 11, further comprising a planarization unit that planarizes a surface of the modeling material layer.   The said addition part has the roller which adds the binder particle carry | supported by the surrounding surface to the said modeling material layer, and the binder particle supply source which supplies the said binder particle to the said roller, From Claim 11 characterized by the above-mentioned. The three-dimensional modeling apparatus according to any one of 13.   The three-dimensional modeling apparatus according to claim 14, wherein a distance between the roller and the modeling material layer is adjustable.   The binder particle supply source supplies the binder particles to the roller such that a width of a region in which the binder particles are supported on a peripheral surface of the roller is the same as a width of the modeling material layer. The three-dimensional modeling apparatus according to claim 14, wherein the three-dimensional modeling apparatus is characterized. The roller is composed of a conductor whose surface is insulated,
The three-dimensional modeling apparatus according to any one of claims 14 to 16, wherein the binder particle supply source supplies the charged binder particles. The addition part is
A photoreceptor,
A charging unit for uniformly charging the photoreceptor;
An exposure unit that performs image exposure on the photoconductor to form an electrostatic latent image; and
The three-dimensional modeling apparatus according to claim 11, further comprising a developing unit that develops the electrostatic latent image with the charged binder particles.   The control unit adds the binder particles by the addition unit each time the modeling material layer is formed by the discharge unit and the modeling material layer is semi-cured by the curing unit. The three-dimensional modeling apparatus according to any one of 14 to 18.