JP6996310B2 - Manufacturing method of three-dimensional model - Google Patents

Description

The present invention relates to a method for manufacturing a three-dimensional model.

The three-dimensional modeling method (hereinafter sometimes referred to as powder layered manufacturing method) for laminating powder materials to create a model is the laser sintering method (LS), electron beam sintering method (EBM), and binder jet method. It is roughly divided. Generally, the binder jet method is a technique of using a powder material, applying a binder ink (modeling liquid) from an inkjet head, and coagulating the powder material to perform modeling. Examples of the powder material include gypsum, various sands, metals, ceramics, glass and the like. Further, there is known a technique of coating these powder materials with a water-soluble organic material and applying a modeling liquid to crosslink the water-soluble organic materials and bond the powder materials to each other (for example, Patent Document 1). reference). After modeling the powder material, for example, after removing the unbonded powder material, a sintering step can be performed to obtain a three-dimensional model as a dense structure.

However, in the conventional powder additive manufacturing method as described above, shrinkage of the three-dimensional model occurs when the sintering step is performed. Depending on the shape of the three-dimensional model, there is a problem that it does not shrink isotropically due to the difference in the progress of sintering and the difference in heat distribution, and the shape distortion due to sintering occurs. This problem becomes more pronounced as the model becomes larger and the shape becomes more complex. In order to suppress such distortion, a method is known in which a support portion is provided at a position where the model portion constituting the three-dimensional model is likely to shrink and sintering is performed. However, in general, the support material that constitutes the support part is sintered together with the model part in the sintering process, so it is essential to integrate the model part and the support part and remove the support part by machining such as cutting. Therefore, there is a problem that a long-time post-treatment process is required.

In addition, Patent Document 2 is characterized in that the outermost layer of the modeled object is provided with a binder 1.05 to 5.0 times the amount of the binder applied to the inside of the modeled object. The manufacturing method is disclosed.
Further, in Patent Document 3, when a curable modeling material is discharged toward a modeling stage to form a modeling material layer, an inner portion of the contour of the three-dimensional model is formed, and then diagonally downward from the inner portion. A three-dimensional modeling method is disclosed in which an inclined portion inclined toward is formed as the contour portion.
However, these conventional techniques cannot solve the problems related to the long-time post-treatment process for removing the support portion as described above.

An object of the present invention is a laminating step of applying a modeling liquid to a powder material to form a modeling layer to which the powder materials are bonded, and sequentially laminating the modeling layers to obtain a laminate, and sintering the laminate. In the method of manufacturing a three-dimensional model having a sintering step, it is easy to remove the support portion that supports the model portion from the model portion constituting the three-dimensional model, and it takes a long time to remove the support portion. It is an object of the present invention to provide a method for manufacturing a three-dimensional model, which can omit a post-treatment step.

The above problem is solved by the following configuration 1).
1) A laminating step of applying a modeling ink B containing water to a powder material to form a modeling layer to which the powder material is bonded, and sequentially laminating the modeling layers to obtain a laminated body, and the laminated body. In a method of manufacturing a three-dimensional molded product having a sintering step of sintering,
During the laminating step, a non-modeling ink A containing a ceramic precursor is applied between a model portion constituting the three-dimensional model and a support portion supporting the model portion, and between the model portion and the support portion. Forming a sintering inhibition region in
A method for producing a three-dimensional model , wherein the ceramic precursor reacts with water contained in the modeling ink B.

According to the present invention, a molding liquid is applied to a powder material to form a molding layer to which the powder materials are bonded, and the molding layers are sequentially laminated to obtain a laminated body, and the laminated body is sintered. In the method of manufacturing a three-dimensional model having a sintering step, it is easy to remove the support portion that supports the model portion from the model portion constituting the three-dimensional model, and it takes a long time to remove the support portion. It is possible to provide a method for manufacturing a three-dimensional model, which can omit the post-treatment step.

It is a plane explanatory view of the three-dimensional modeling apparatus which concerns on embodiment of this invention. It is a side explanatory view of the three-dimensional modeling apparatus which concerns on embodiment of this invention. It is sectional drawing at the time of modeling part. It is a perspective explanatory drawing of the three-dimensional modeling apparatus which concerns on embodiment of this invention. It is a perspective explanatory view of the modeling part. It is a block diagram of the control part of the three-dimensional modeling apparatus which concerns on embodiment of this invention. It is a schematic explanatory drawing provided for the explanation of the flow of modeling which concerns on embodiment of this invention. It is a schematic explanatory drawing provided for the explanation of the flow of another modeling which concerns on embodiment of this invention. It is a perspective view of an example of a three-dimensional model. It is a perspective view for demonstrating the state of the model part and the support part in the prior art. It is a perspective view for demonstrating the state of the model part and the support part in this invention. It is a figure for demonstrating an example of the application pattern of the non-modeling ink A. It is a figure for demonstrating an example of the application pattern of the non-modeling ink A. It is a figure for demonstrating an example of the ejection method of the modeling ink B and the non-modeling ink A. It is a figure for demonstrating another example of the ejection method of the modeling ink B and the non-modeling ink A. It is a figure for demonstrating an example of the mechanism which a thin film is formed between a model part and a support part. It is a figure for demonstrating another example of the mechanism which a thin film is formed between a model part and a support part.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. An outline of the first example of the three-dimensional modeling apparatus according to the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a plan explanatory view of the three-dimensional modeling apparatus according to the embodiment of the present invention, FIG. 2 is a side view of the three-dimensional modeling apparatus according to the embodiment of the present invention, and FIG. 3 is a cross section of a modeling portion. It is an explanatory view, FIG. 4 is a perspective explanatory view of the three-dimensional modeling apparatus which concerns on embodiment of this invention, and FIG. 5 is a perspective explanatory view of a modeling part.

This three-dimensional modeling device is a powder modeling device (also referred to as a powder modeling device), and is a modeling unit 1 in which a modeling layer 30 which is a layered model to which powder (powder material) is bonded is formed, and modeling. A modeling unit 5 for forming a three-dimensional model by ejecting a modeling liquid 10 (modeling ink B) into a powder layer 31 spread over the layers of the portion 1 is provided.

The modeling unit 1 includes a powder tank 11 and a flattening roller 12 as a rotating body which is a flattening member (recoater). The flattening member may be, for example, a plate-shaped member (blade) instead of the rotating body.

The powder tank 11 has a supply tank 21 for supplying the powder 20 and a modeling tank 22 on which the modeling layer 30 is laminated to form a three-dimensional model. The bottom of the supply tank 21 can be raised and lowered in the vertical direction (height direction) as the supply stage 23. Similarly, the bottom of the modeling tank 22 can be raised and lowered in the vertical direction (height direction) as the modeling stage 24. A three-dimensional model in which the modeling layer 30 is laminated on the modeling stage 24 is modeled.

As shown in FIG. 4, for example, the supply stage 23 is moved up and down in the arrow Z direction (height direction) by the motor 27, and the modeling stage 24 is also moved up and down in the arrow Z direction by the motor 28.

The flattening roller 12 supplies the powder 20 supplied on the supply stage 23 of the supply tank 21 to the modeling tank 22 and flattens the powder layer 31 by the flattening roller 12 which is a flattening member. To form.

The flattening roller 12 is arranged so as to be reciprocating relative to the stage surface in the direction of arrow Y along the stage surface (the surface on which the powder 20 is loaded) of the modeling stage 24, and the reciprocating moving mechanism 25 is provided. Moved by. Further, the flattening roller 12 is rotationally driven by the motor 26.

On the other hand, the modeling unit 5 includes a liquid discharge unit 50 that discharges the modeling liquid 10 to the powder layer 31 on the modeling stage 24.

The liquid discharge unit 50 includes a carriage 51 and two (one or three or more) liquid discharge heads (hereinafter, simply referred to as “heads”) 52a and 52b mounted on the carriage 51.

The carriage 51 is movably held by the guide members 54 and 55. The guide members 54 and 55 are held on the side plates 70 and 70 on both sides so as to be able to move up and down.

The carriage 51 is referred to as an arrow X direction (hereinafter, simply referred to as “X direction”) which is the main scanning direction via a main scanning moving mechanism composed of a motor, a pulley and a belt by an X direction scanning mechanism 550 described later. , Z is also moved back and forth.

In the two heads 52a and 52b (hereinafter, referred to as "head 52" when not distinguished), two rows of nozzles in which a plurality of nozzles for discharging liquid are arranged are arranged. The two nozzle rows of one head 52a discharge the cyan modeling liquid and the magenta modeling liquid. The two nozzle rows of the other head 52b discharge the yellow modeling liquid and the black modeling liquid, respectively. The head configuration is not limited to this.

A plurality of tanks 60 containing each of these cyan modeling liquid, magenta modeling liquid, yellow modeling liquid, and black modeling liquid are mounted on the tank mounting portion 56 and supplied to the heads 52a and 52b via a supply tube and the like.

Further, in the carriage 51, when forming one modeling layer 30 in the modeling tank 22, the powder post-supply unit, which is a powder post-supply means for supplying the powder 20 to at least the region to which the modeling liquid 10 is attached. 80 is provided integrally.

Further, on one side in the X direction, a maintenance mechanism 61 for maintaining and recovering the head 52 of the liquid discharge unit 50 is arranged.

The maintenance mechanism 61 is mainly composed of a cap 62 and a wiper 63. The cap 62 is brought into close contact with the nozzle surface (the surface on which the nozzle is formed) of the head 52, and the modeling liquid is sucked from the nozzle. This is to discharge the powder clogged in the nozzle and the highly viscous modeling liquid. After that, in order to form the meniscus of the nozzle (the inside of the nozzle is in a negative pressure state), the nozzle surface is wiped (wiped) with the wiper 63. Further, the maintenance mechanism 61 covers the nozzle surface of the head with the cap 62 when the modeling liquid is not discharged, and prevents the powder 20 from being mixed into the nozzle and the modeling liquid 10 from drying.

The modeling unit 5 has a slider portion 72 movably held by a guide member 71 arranged on the base member 7, and the entire modeling unit 5 reciprocates in the Y direction (sub-scanning direction) orthogonal to the X direction. It is possible. The entire modeling unit 5 is reciprocated in the Y direction by the Y-direction scanning mechanism 552 described later.

The liquid discharge unit 50 is arranged so as to be able to move up and down in the Z direction of the arrow together with the guide members 54 and 55, and is moved up and down in the Z direction by the Z direction raising and lowering mechanism 551 described later.

Here, the details of the modeling unit 1 will be described.

The powder tank 11 has a box shape and includes two tanks having an open upper surface, a supply tank 21 and a modeling tank 22. A supply stage 23 is arranged inside the supply tank 21, and a modeling stage 24 is arranged inside the modeling tank 22 so as to be able to move up and down.

The side surface of the supply stage 23 is arranged so as to be in contact with the inner side surface of the supply tank 21. The side surface of the modeling stage 24 is arranged so as to be in contact with the inner surface surface of the modeling tank 22. The upper surfaces of these supply stages 23 and the modeling stage 24 are kept horizontal.

As shown in FIG. 5, a concave powder drop port 29 having an open upper surface is provided around the powder tank 11 (omitted in FIGS. 1 to 3). The excess powder 20 of the powder 20 supplied by the flattening roller 12 when the powder layer 31 is formed falls into the powder drop port 29. The excess powder 20 that has fallen into the powder drop port 29 is returned to the powder supply device that supplies the powder to the supply tank 21.

The powder supply device 554 of FIG. 6 is arranged on the supply tank 21. During the initial operation of modeling or when the amount of powder in the supply tank 21 decreases, the powder in the tank constituting the powder supply device 554 is supplied to the supply tank 21. Examples of the powder transfer method for powder supply include a screw conveyor method using a screw and an air transport method using air.

The flattening roller 12 transfers and supplies the powder 20 from the supply tank 21 to the modeling tank 22 and flattens the surface by leveling the powder layer 31 to form a layered powder having a predetermined thickness. ..

The flattening roller 12 is a rod-shaped member longer than the inner dimensions of the modeling tank 22 and the supply tank 21 (that is, the width of the portion where the powder is supplied or the portion where the powder is charged), and is staged by the reciprocating movement mechanism 25. It is reciprocated in the Y direction (secondary scanning direction) along the surface.

The flattening roller 12 moves horizontally while being rotated by the motor 26 so as to pass above the supply tank 21 and the modeling tank 22 from the outside of the supply tank 21. As a result, the powder 20 is transferred and supplied onto the modeling tank 22, and the powder layer 31 is formed by flattening the powder 20 while the flattening roller 12 passes over the modeling tank 22.

Further, as shown in FIG. 2, a powder removing plate 13 which is a powder removing member for removing the powder 20 adhering to the flattening roller 12 in contact with the peripheral surface of the flattening roller 12 is arranged. Has been done.

The powder removing plate 13 moves together with the flattening roller 12 in a state of being in contact with the peripheral surface of the flattening roller 12. Further, the powder removing plate 13 is arranged so as to be in the counter direction when the flattening roller 12 rotates in the rotation direction when flattening.

In the present embodiment, the powder tank 11 of the modeling unit 1 has two tanks, a supply tank 21 and a modeling tank 22, but only the modeling tank 22 is used to supply powder from the powder supply device to the modeling tank 22. It can also be supplied and flattened by a flattening means.

Next, the outline of the control unit of the three-dimensional modeling apparatus will be described with reference to FIG. FIG. 6 is a block diagram of the control unit.

The control unit 500 includes a CPU 501 that controls the entire three-dimensional modeling apparatus, a program including a program for causing the CPU 501 to execute control of the three-dimensional modeling operation including the control according to the present invention, and a ROM 502 that stores other fixed data. , A main control unit 500A including a RAM 503 for temporarily storing modeling data and the like.

The control unit 500 includes a non-volatile memory (NVRAM) 504 for holding data even while the power of the device is cut off. Further, the control unit 500 includes an ASIC 505 that processes an image process that performs various signal processes on the image data and other input / output signals for controlling the entire device.

The control unit 500 includes an I / F 506 for transmitting and receiving data and signals used when receiving modeling data from an external modeling data creating device 600. The modeling data creating device 600 is a device that creates modeling data by slicing a modeled object in the final form into each modeling layer, and is composed of an information processing device such as a personal computer.

The control unit 500 includes an I / O 507 for capturing detection signals of various sensors.

The control unit 500 includes a head drive control unit 508 that drives and controls each head 52 of the liquid discharge unit 50.

The control unit 500 drives the motor drive unit 510 that drives the motor constituting the X-direction scanning mechanism 550 that moves the carriage 51 of the liquid discharge unit 50 in the X direction (main scanning direction), and the modeling unit 5 in the Y direction (sub-scanning). It includes a motor drive unit 512 that drives a motor constituting the Y-direction scanning mechanism 552 that moves in the direction (direction).

The control unit 500 includes a motor drive unit 511 that drives a motor constituting a Z-direction elevating mechanism 551 that moves (elevates) the carriage 51 of the liquid discharge unit 50 in the Z direction. It should be noted that the elevating and lowering in the direction of the arrow Z may be configured to elevate and lower the entire modeling unit 5.

The control unit 500 includes a motor drive unit 513 that drives the motor 27 that raises and lowers the supply stage 23, and a motor drive unit 514 that drives the motor 28 that raises and lowers the modeling stage 24.

The control unit 500 includes a motor drive unit 515 that drives the motor 553 of the reciprocating movement mechanism 25 that moves the flattening roller 12, and a motor drive unit 516 that drives the motor 26 that rotationally drives the flattening roller 12.

The control unit 500 includes a supply system drive unit 517 that drives the powder supply device 554 that supplies the powder 20 to the supply tank 21, and a maintenance drive unit 518 that drives the maintenance mechanism 61 of the liquid discharge unit 50.

A detection signal such as a temperature / humidity sensor 560 that detects temperature and humidity as an environmental condition of the device and a detection signal of other sensors are input to the I / O 507 of the control unit 500.

An operation panel 522 for inputting and displaying information necessary for this device is connected to the control unit 500.

The modeling data creation device 600 and the three-dimensional modeling device (powder laminated modeling device) 601 constitute a three-dimensional modeling system as the device according to the present invention.

Next, the flow of modeling will be described with reference to FIG. 7. FIG. 7 is a schematic explanatory diagram for explaining the flow of modeling.

The state in which the first modeling layer 30 is formed on the modeling stage 24 of the modeling tank 22 will be described.

When the next modeling layer 30 is formed on the modeling layer 30, as shown in FIG. 7A, the supply stage 23 of the supply tank 21 is raised in the Z1 direction, and the modeling stage 24 of the modeling tank 22 is moved in the Z2 direction. To descend to.

At this time, the descending distance of the modeling stage 24 is set so that the distance between the upper surface (powder layer surface) of the modeling tank 22 and the lower portion (lower tangential portion) of the flattening roller 12 is Δt1. This interval Δt1 corresponds to the thickness of the powder layer 31 to be formed next. The interval Δt1 is preferably about several tens to 100 μm.

Next, as shown in FIG. 7B, the powder 20 located above the upper surface level of the supply tank 21 is rotated in the Y2 direction (modeling tank 22) while rotating the flattening roller 12 in the forward direction (arrow direction). By moving to the side), the powder 20 is transferred and supplied to the modeling tank 22 (powder supply).

Further, as shown in FIG. 7C, the flattening roller 12 is moved in parallel with the stage surface of the modeling stage 24 of the modeling tank 22, and as shown in FIG. 7D, the modeling layer 30 of the modeling stage 24 is moved. The powder layer 31 having a predetermined thickness Δt1 is formed above (flattening). After forming the powder layer 31, the flattening roller 12 is moved in the Y1 direction and returned to the initial position as shown in FIG. 7D.

Here, the flattening roller 12 can move while keeping a constant distance from the upper surface levels of the modeling tank 22 and the supply tank 21. By being able to move while being kept constant, the powder 20 having a uniform thickness Δt1 is conveyed on the modeling tank 22 or on the already formed modeling layer 30 while the powder 20 is conveyed onto the modeling tank 22 by the flattening roller 12. The layer 31 can be formed.

After that, as shown in FIG. 7 (e), droplets of the modeling liquid 10 are ejected from the head 52 of the liquid ejection unit 50 to laminate and form the modeling layer 30 on the next powder layer 31 (modeling).

In the modeling layer 30, for example, the modeling liquid 10 discharged from the head 52 is mixed with the powder 20, so that the water-soluble organic material contained in the powder 20 is crosslinked by the cross-linking agent contained in the modeling liquid 10. And the powders are bonded to each other to form.

Next, a new molding layer 30 is formed by repeating the above-mentioned steps of forming the powder layer 31 by powder supply and flattening and the molding liquid discharge step by the head 52. At this time, the new modeling layer 30 and the underlying modeling layer 30 are integrated to form a part of the three-dimensional shaped object.

After that, the three-dimensional shape model (three-dimensional model) is completed by repeating the process of forming the powder layer 31 by supplying and flattening the powder and the process of discharging the modeling liquid by the head 52 as many times as necessary.

Next, as a second example, the flow of modeling in the powder layer forming method will be described with reference to FIG. FIG. 8 is a schematic explanatory diagram for explaining the flow of modeling.

Here, the state in which the first modeling layer 30 is formed on the modeling stage 24 of the modeling tank 22 will be described.

When the next modeling layer 30 is formed on the modeling layer 30, as shown in FIG. 8A, the supply stage 23 of the supply tank 21 is raised in the Z1 direction, and the modeling stage 24 of the modeling tank 22 is moved in the Z2 direction. To descend to.

At this time, the descending distance of the modeling stage 24 is preferably larger than Δt1 and more preferably twice or less of Δt1. The interval Δt1 corresponds to the thickness (stacking pitch) of the powder layer to be formed next. The interval Δt1 is preferably about several tens to 100 μm.

In this case, the flattening roller 12 is arranged with a gap between the upper end surfaces of the supply tank 21 and the modeling tank 22. Therefore, when the powder is transferred and supplied to the modeling tank 22 for flattening, the surface (powder surface) of the powder layer is higher than the upper end surfaces of the supply tank 21 and the modeling tank 22.

As a result, the flattening roller 12 can be reliably prevented from coming into contact with the upper end surfaces of the supply tank 21 and the modeling tank 22, and damage to the flattening roller 12 is reduced. When the surface of the flattening roller 12 is damaged, streaks are generated on the surface of the powder layer and the flatness is lowered.

Next, as shown in FIG. 8B, the powder 20 located above the upper surface level of the supply tank 21 is moved to the modeling tank 22 side while rotating the flattening roller 12 in the opposite direction (arrow direction). By doing so, the powder 20 is transferred and supplied to the modeling tank 22 (powder supply).

Further, as shown in FIG. 8C, the flattening roller 12 is moved in parallel with the stage surface of the modeling stage 24 of the modeling tank 22, and the powder layer 31 thicker than Δt1 is formed on the modeling layer of the modeling stage 24. Form. At this time, the excess powder not used for forming the powder layer 31 falls into the excess powder receiving tank.

After that, as shown in FIG. 8D, the modeling tank stage 24 is raised and the supply tank stage 23 is lowered so that the distance between the modeled object and the moving line of the flattening roller is Δt1.

Then, as shown in FIG. 8 (e), the flattening roller 12 is moved to the supply tank 21 side while rotating in the direction of the arrow, and the surplus powder is returned to the supply tank 21 to raise the powder surface of the modeling tank. Flatten.

In the second powder layer forming method in which the supply tank 21 is flattened when the flattening roller 12 returns to the origin, not only the amount of excess powder carried to the excess powder receiving tank during powder transfer is reduced, but also the powder is powdered. It has the effect of improving the smoothness of the body layer and increasing the powder density.

After that, as shown in FIG. 8 (g), droplets of the modeling liquid 10 are ejected from the head 52 of the liquid ejection unit to laminate and form a modeling layer having a required shape on the next powder layer (modeling). At this time, the modeling liquid 10 is discharged in a plurality of times for one section.

In the modeling layer, for example, the modeling liquid discharged from the head is mixed with the powder, so that the water-soluble organic material contained in the powder is crosslinked by the cross-linking agent contained in the modeling liquid, and the powders are separated from each other. Formed by being combined.

Next, a new modeling layer is formed by repeating the above-mentioned steps of forming the powder layer by powder supply and flattening and the process of discharging the modeling liquid by the head. At this time, the new modeling layer and the underlying modeling layer are integrated to form a part of the three-dimensional shaped object (three-dimensional model).

After that, the three-dimensional shape model (three-dimensional model) is completed by repeating the process of forming the powder layer by supplying and flattening the powder and the process of discharging the modeling liquid by the head as many times as necessary.

Next, an example of the three-dimensional modeling powder material (powder) and the modeling ink B (modeling liquid) used in the three-dimensional modeling apparatus will be described. It should be noted that the present invention is not limited to the powder and the modeling liquid described below.

The powder material for three-dimensional modeling has a base material and a water-soluble organic material that covers the base material with an average thickness of 5 nm to 500 nm and can be dissolved and crosslinked by the action of water containing a cross-linking agent as a modeling liquid. Become.

In this powder material for three-dimensional modeling, the water-soluble organic material that coats the base material can be dissolved and crosslinked by the action of the cross-linking agent-containing water. The water-soluble organic material dissolves and is crosslinked by the action of the crosslinking agent contained in the crosslinking agent-containing water.

As a result, a thin layer (powder layer) was formed using the above-mentioned powder material for three-dimensional modeling, and water containing a cross-linking agent was discharged as the modeling liquid 10 into the powder layer, whereby the powder layer was dissolved. As a result of the cross-linking of the water-soluble organic material, the powder layer is bonded and hardened to form the modeling layer 30.

At this time, the coating amount of the water-soluble organic material covering the base material is preferably 5 nm to 500 nm in average thickness, so that when the water-soluble organic material is dissolved, only the minimum necessary amount is present around the base material. Since this is crosslinked to form a three-dimensional network, the powder layer is cured with good dimensional accuracy and good strength.

By repeating this operation, it is possible to easily and efficiently form a complicated three-dimensional model with good dimensional accuracy without causing shape loss before sintering or the like.

-Base material-
As the base material, a metal that can be finally sintered is selected. For example, stainless steel (SUS) steel, iron, copper, titanium, silver and the like are preferably mentioned, and examples of the stainless steel (SUS) steel include SUS316L and the like.

These materials may be used alone or in combination of two or more.

As the base material, commercially available particles or powders made of these materials can be used. Examples of commercially available products include SUS316L (Sanyo Special Steel, PSS316L) and Ti (Osaka Titanium).

Further, the base material may be subjected to a known surface (modification) treatment for the purpose of enhancing the affinity with the water-soluble organic material.

-Water-soluble organic material-
The water-soluble organic material is not particularly limited as long as it is soluble in water and has the property of being crosslinkable by the action of a cross-linking agent, in other words, as long as it is water-soluble and can be crosslinked by a cross-linking agent. , Can be appropriately selected according to the purpose.

Here, the water solubility of the water-soluble organic material means that, for example, when 1 g of the water-soluble organic material is mixed with 100 g of water at 30 ° C. and stirred, 90% by mass or more thereof is dissolved.

The water-soluble organic material preferably has a viscosity of a 4% by mass (w / w%) aqueous solution at 20 ° C. of 40 mPa · s or less, and more preferably 1 to 35 Pa · s. Those having an amount of about 30 mPa · s are particularly preferable.

When the viscosity of the water-soluble organic material is 40 mPa · s or less, the powder material for three-dimensional modeling (powder layer) formed by applying water containing a cross-linking agent, which is a molding liquid, to the powder material for three-dimensional modeling. The strength of the cured product (three-dimensional molded product, cured product for sintering) becomes sufficient, and problems such as shape loss are less likely to occur during subsequent processing or handling such as sintering. In addition, the dimensional accuracy of the cured product (three-dimensional model, cured product for sintering) formed by the powder material for three-dimensional modeling (powder layer) formed by applying cross-linking agent-containing water to the powder material for three-dimensional modeling is sufficient. Will be.

The viscosity of the water-soluble organic material can be measured, for example, according to JIS K7117.

-Water containing cross-linking agent-
The cross-linking agent-containing water as the modeling liquid is not particularly limited as long as it contains the cross-linking agent in the aqueous medium, and can be appropriately selected depending on the intended purpose. The cross-linking agent-containing water may contain an aqueous medium, a cross-linking agent, and other components appropriately selected as necessary.

The other components can be appropriately selected in consideration of various conditions such as the type of means for applying the cross-linking agent-containing water, the frequency of use and the amount. For example, when water containing a cross-linking agent is applied by the liquid discharge method, it can be selected in consideration of the influence of clogging of the liquid discharge head on the nozzle.

Examples of the aqueous medium include water, alcohols such as ethanol, ethers, ketones, and the like, but water is preferable. The aqueous medium may be one in which water contains a small amount of a component other than water such as alcohol.

By using the above-mentioned powder material for three-dimensional modeling and water containing a cross-linking agent as the modeling liquid, the nozzle is compared with the configuration in which the binder for adhering the powder (base material) is discharged from the liquid discharge head. There is less clogging and the durability of the head is improved.

In the manufacturing method of the present invention, a non-modeling ink A that facilitates removal of the support portion from the model portion is applied between the model portion constituting the three-dimensional model and the support portion that supports the model portion, and both are applied. It is characterized by forming a sintering inhibition region between them. The non-modeling ink A is a model by using a conventionally known method, for example, an inkjet method, or by further providing another liquid ejection head in the three-dimensional modeling apparatus described with reference to FIGS. 1 to 8 and ejecting the non-modeling ink A. A sintering inhibition region can be formed between the portion and the support portion.

FIG. 9 is a perspective view of an example of a three-dimensional model for explaining the method of the present invention. The three-dimensional model 90 shown in FIG. 9 is a model in which an arch 92 overhanging the plate 91 is formed. When modeling is performed by the conventional method, a support portion 93 made of a support material for supporting the arch is required at the lower part of the arch 92 as shown in FIG. If there is no support portion 93, it is difficult to form the structure of the arch 92, and even if it can be formed, the shape will be distorted due to heat shrinkage. Further, the support unit 93 requires a long-time post-processing step of removing the support unit 93 from the modeled object by machining or the like as described above, and the shape cannot be modeled in a complicated shape that cannot be machined.

Therefore, in the present invention, as shown in FIG. 11, a non-modeling ink A is applied between the model portion, which is the arch 92, and the support portion 93, and a sintering inhibition region is formed between the two. The sintering inhibition region is preferably a thin film 94 made of a solid component of the non-modeling ink A. Such a thin film 94 is more preferably a thin film containing a ceramic powder or a ceramic precursor. Generally, in the powder additive manufacturing method, a dense structure is obtained by sequentially laminating the modeling layers to obtain a laminated body and then performing a sintering step on the laminated body. In the embodiment of the present invention, a ceramic thin film is formed between the model portion and the support portion by the sintering step, and the fixing between the model portion and the support portion due to sintering is prevented. This facilitates the separation of the model unit and the support unit without performing the post-processing process by machining as in the conventional case.

Examples of the non-modeling ink A include those containing a ceramic precursor. The ceramic precursor preferably forms a three-dimensional network structure having an —Si—O— bond by hydrolysis, and examples thereof include alkoxysilanes such as tetramethyl orthosilicate (TEOS). The ceramic precursor contained in the non-modeling ink A can react with, for example, a component (specifically, water) contained in the modeling ink B to form the three-dimensional network structure.
Apart from this, the non-modeling ink A may also contain ceramic powder. Examples of the ceramic powder include silica and the like.

12 and 13 are diagrams for explaining an example of a coating pattern of the non-modeling ink A.
In FIG. 12, (a) is a perspective view of an example of a three-dimensional model as in FIG. 9, and (b) is a plan view of a cross section of the boundary portion between the plate member 91 and the arch 92 along the line AA. .. In FIG. 12B, the non-modeling ink A is applied to the entire portion of the support portion 93 facing the plate material 91 to form the thin film 94.
In FIG. 13, (a) is a perspective view of an example of a three-dimensional model as in FIG. 9, and (b) is a plan view of a cross section of the arch 92 along the line BB. In FIG. 12B, the non-modeling ink A is applied to the contact surface between the support portion 93 and the arch 92 to form the thin film 94.
The thickness of the thin film 94 can be variously determined depending on the constituent components of the non-modeling ink A. For example, as the thickness after the firing step, the distance between the model portion and the support portion is not adjacent to each other at least in voxel units. It is necessary to provide. The term "adjacent" here includes not only front-back, up-down, left-right, but also voxel in the diagonal direction with respect to the reference voxel. At this time, in the formation of the image pattern, particularly the formation of the image pattern at the interface between the model part-thin film-support part, the model part is given first priority, the range of the thin film is determined according to the image of the modeled object, and then the support is performed. Determine the image of the part.

FIG. 14 is a diagram for explaining an example of a method of ejecting the modeling ink B and the non-modeling ink A, and FIG. 15 is a diagram showing another example of the ejection method of the modeling ink B and the non-modeling ink A. It is a figure for demonstrating.
In the form shown in FIG. 14, the modeling ink B and the non-modeling ink A are simultaneously ejected to the powder material, and each ink wets and spreads over a predetermined region in the powder material 200.
In the form shown in FIG. 15, the non-modeling ink A is first ejected, and then the modeling ink B is ejected. In this embodiment, the non-modeling ink A is sufficiently wet and spread over a predetermined area in the powder material 200 and then comes into contact with water contained in the modeling ink B, so that the non-modeling ink A is made of ceramic. When the precursor is contained, a three-dimensional network structure having an —Si—O— bond is formed, and after the sintering step, the solid component contained in the non-modeling ink A is between the powder materials. It becomes easy to remove the support part from the model part.

FIG. 16 is a diagram for explaining an example of a mechanism in which a thin film is formed between a model portion and a support portion.
In the form shown in FIG. 16, the non-modeling ink A contains a ceramic precursor. By ejecting the modeling ink B, water is supplied to the non-modeling ink A to form a three-dimensional network structure having an —Si—O— bond. After the sintering step, the solid component contained in the non-modeling ink A is transferred to the ceramic, intervenes between the powder materials, and the support portion can be easily removed from the model portion. Generally, the ceramic transition temperature of alkoxysilane is 600 to 800 ° C., which is sufficiently lower than the sintering temperature (1000 ° C. or higher) of a powder material made of metal. Therefore, a ceramic thin film is formed between the model portion and the support portion before the sintering shrinkage progresses and before both are fixed, so that the support portion can be easily removed from the model portion. Become.

FIG. 17 is a diagram for explaining another example of the mechanism by which a thin film is formed between the model portion and the support portion.
In the form shown in FIG. 17, the non-modeling ink A contains a ceramic powder.
In the process of ejecting and drying the non-modeling ink A, the ceramic powder is interposed between the powder materials. After that, when the temperature at which the sintering shrinkage progresses is reached, the powder materials whose contacts are blocked by the ceramic powder do not proceed with sintering because the distance between the particles is large, and their adhesion to each other is hindered. In this way, the model part and the support part can be easily separated by forming a non-sintered region between the model part and the support part and lowering the mechanical strength through the subsequent sintering step. can.

Specific examples of each material that can be used in the present invention are shown below, but the present invention is not limited to the following examples.
(1)
Base material: SUS316L Average particle size 8 μm
Water-soluble organic material: Polyvinyl alcohol Film thickness 100 μm
Modeling ink B: Water (75%) and non-modeling ink A containing Zr ²⁺ cross-linking agent: Isopropyl alcohol, 1,2-propanediol and ethyl tetraorthosilicate (2)
Base material: SUS316L Average particle size 8 μm
Water-soluble organic material: Polyvinyl alcohol Film thickness 100 μm
Modeling ink B: Water (75%) and non-modeling ink A containing Zr ²⁺ cross-linking agent: isopropyl alcohol, 1,2-propanediol and dimethylsiloxane (3)
Base material: SUS316L Average particle size 8 μm
Water-soluble organic material: Polyvinyl alcohol Film thickness 100 μm
Modeling ink B: Water (75%) and second ink containing Zr ²⁺ cross-linking agent: Isopropyl alcohol, 1,2-propanediol and silica fine particles (average particle size 500 nm)

1 Modeling unit 5 Modeling unit 7 Base member 10 Modeling liquid 11 Powder tank 12 Flattening roller 13 Powder removing plate 20 Powder 21 Supply tank 22 Modeling tank 23 Supply stage 24 Modeling stage 25 Reciprocating movement mechanism 26 Motor 27 Motor 28 Motor 29 Powder drop port 30 Modeling layer 31 Powder layer 50 Liquid discharge unit 51 Carriage 52 Head 52a Liquid discharge head 52b Liquid discharge head 54 Guide member 55 Guide member 56 Tank mounting part 60 Tank 61 Maintenance mechanism 62 Cap 63 Wiper 70 Side plate 71 Guide member 72 Slider unit 80 Powder after-supply unit 500 Control unit 500A Main control unit 501 CPU
502 ROM
503 RAM
504 Non-volatile memory 505 ASIC
506 I / F
507 I / O
508 Head drive control unit 510 Motor drive unit 511 Motor drive unit 512 Motor drive unit 513 Motor drive unit 514 Motor drive unit 515 Motor drive unit 516 Motor drive unit 517 Supply system drive unit 518 Maintenance drive unit 522 Operation panel 550 X-direction scanning mechanism 551 Z-direction scanning mechanism 552 Y-direction scanning mechanism 554 Powder supply device 560 Temperature / humidity sensor 600 Modeling data creation device 601 Three-dimensional modeling device 90 Three-dimensional modeling device 91 Plate material 92 Arch 93 Support part 94 Thin film 200 Powder material

Japanese Unexamined Patent Publication No. 2017-196811 Japanese Unexamined Patent Publication No. 2005-88432 Japanese Unexamined Patent Publication No. 2016-55603

Claims (8)

A molding step in which a modeling ink B containing water is applied to a powder material to form a modeling layer to which the powder material is bonded, and the modeling layers are sequentially laminated to obtain a laminate, and the laminate is sintered. In the method of manufacturing a three-dimensional model having a sintering step
During the laminating step, a non-modeling ink A containing a ceramic precursor is applied between a model portion constituting the three-dimensional model and a support portion supporting the model portion, and between the model portion and the support portion. Forming a sintering inhibition region in
A method for producing a three-dimensional model , wherein the ceramic precursor reacts with water contained in the modeling ink B. The method for producing a three-dimensional model according to claim 1, wherein the sintering inhibition region is formed by a thin film made of a solid component of the non-modeling ink A. The three-dimensional modeling according to claim 1 or 2 , wherein the ceramic precursor reacts with water contained in the modeling ink B to form a three-dimensional network structure having an —Si—O— bond. How to make things. The method for producing a three-dimensional model according to any one of claims 1 to 3 , wherein the ceramic precursor becomes a ceramic thin film by heat equal to or lower than the sintering temperature of the powder material. The three-dimensional model according to any one of claims 1 to 4 , wherein the solid component contained in the non-modeling ink A is interposed between the powder materials by applying the non-modeling ink A. Manufacturing method. The method for producing a three-dimensional model according to any one of claims 1 to 5, wherein the powder material has a base material and a water-soluble organic material that coats the base material. The method for producing a three-dimensional model according to claim 6, wherein the modeling ink B contains water containing a cross-linking agent. The method for producing a three-dimensional model according to any one of claims 1 to 7, wherein the non-modeling ink A contains a ceramic powder.

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