JP2011230422A - Method for producing stereoscopically shaped article, the stereoscopically shaped article, stereoscopically shaping powder, and stereoscopically shaping apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a stereoscopically shaped article, by which the stereoscopically shaped article where the interlayer of a shaped solid hardly exfoliates can be shaped and to provide the stereoscopically shaped article, stereoscopically shaping powder, and a stereoscopically shaping apparatus.SOLUTION: In the stereoscopically shaping apparatus, the stereoscopically shaping powder containing a water-soluble polymer is fed onto a placing belt (S2). The water-soluble polymer in the stereoscopically shaping powder contains partial saponification type polyvinyl alcohol. In the stereoscopically shaping apparatus, shaping liquid is ejected to the stereoscopically shaping powder from an inkjet head to mix the shaping liquid with the stereoscopically shaping powder. Consequently a solid layer which has a product produced by melting the partial saponification type polyvinyl alcohol included in the stereoscopically shaping powder in the shaping liquid, is formed (S3). Lamination of the layers forms the stereoscopically shaped article of a shape desired by a worker.

Description

  The present invention forms a three-dimensional object that is formed by mixing and solidifying a modeling liquid and a three-dimensional object powder, a three-dimensional object, a three-dimensional object powder, and a three-dimensional object. The present invention relates to a three-dimensional modeling apparatus.

  2. Description of the Related Art Conventionally, a technique for modeling a three-dimensional model by mixing a three-dimensional model powder and a modeling liquid to solidify is known (for example, see Patent Document 1). The powder described in Patent Document 1 includes an adhesive, a filler, and fibers. As an adhesive contained in the powder, a water-soluble polymer such as polyvinyl alcohol is disclosed. When the modeling liquid using water as a solvent is mixed with the powder, the adhesive contained in the powder is dissolved. The dissolved adhesives are bonded together to form a layer. More specifically, a solid layer is obtained by dropping the modeling liquid onto the powder placed on the mounting table by an inkjet head or the like. When the above processes are repeated and the solid layers are stacked, a three-dimensional object having a shape desired by the operator is formed.

Japanese Patent No. 3607300

  However, when a solid layer is modeled using the three-dimensional modeling powder as described in Patent Document 1, depending on the three-dimensional modeling powder to be used, there is a problem that the layer of the modeled solid material peels and warps. there were. Therefore, it has been difficult to form a solid three-dimensional object into a desired shape.

  It is an object of the present invention to provide a manufacturing method of a three-dimensional modeled object, a three-dimensional modeled object, a three-dimensional modeled powder, and a three-dimensional modeled apparatus capable of modeling a three-dimensional modeled object in which the layers of the modeled solid object are difficult to peel off. To do.

  The manufacturing method of the three-dimensional molded item according to the first aspect of the present invention includes a layer forming step of forming a layer with a three-dimensional molded powder containing a water-soluble polymer, and water in the layer formed in the layer forming step. And a production process for producing a layer having a product produced by dissolving the three-dimensional modeling powder in the modeling liquid by dropping a modeling liquid using a solvent as a solvent, The water-soluble polymer contains partially saponified polyvinyl alcohol. It is difficult to peel off the solid layers generated by the method for manufacturing a three-dimensional structure according to the first aspect. Therefore, a three-dimensional molded item can be modeled in a desired shape.

  The partially saponified polyvinyl alcohol contained in the water-soluble polymer may have a particle size of 250 μm or less. In this case, the surface of the three-dimensional modeling powder can be smoothed. Therefore, the thickness of the layer of the three-dimensional modeling powder can be easily adjusted, and a three-dimensional modeled object having a desired shape can be modeled more accurately.

  The three-dimensional shaped powder may contain, as a filler, an inorganic material or an organic material having an average particle diameter of 9 μm or more and 40 μm or less and having no adhesive force. By including the filler in the three-dimensional modeled powder, shrinkage of the three-dimensional modeled product due to evaporation of water is suppressed. Therefore, it is possible to model a three-dimensional model with high dimensional accuracy.

  The three-dimensional shaped powder may contain calcium carbonate having an average particle diameter of 9 μm or more and 40 μm or less as a filler. By including the filler in the three-dimensional modeled powder, shrinkage of the three-dimensional modeled product due to evaporation of water is suppressed. Furthermore, by using calcium carbonate as a filler, it is possible to suppress the three-dimensional shaped powder from being scattered.

  The three-dimensional structure according to the second aspect of the present invention is formed by laminating products formed from a three-dimensional structure powder containing a water-soluble polymer and a modeling liquid containing water as a solvent. The water-soluble polymer contains partially saponified polyvinyl alcohol. As for the three-dimensional molded item which concerns on a 2nd aspect, the interlayer of the solid substance produced | generated in the process of manufacture is hard to peel.

  The three-dimensional modeling powder according to the third aspect of the present invention contains a water-soluble polymer, and a three-dimensional modeled object layer is formed by adding a modeling liquid containing water as a solvent and dissolving it in the modeling liquid. A shaped powder, wherein the water-soluble polymer contains partially saponified polyvinyl alcohol. According to the three-dimensionally shaped powder according to the third aspect, it is possible to generate a solid layer in which the layers are not easily separated. Therefore, a three-dimensional molded item can be modeled in a desired shape.

  The three-dimensional modeling apparatus according to the fourth aspect of the present invention includes a mounting table for mounting a three-dimensional modeling powder containing partially saponified polyvinyl alcohol as a water-soluble polymer, and an inkjet capable of discharging a modeling liquid using water as a solvent. It was mounted on the mounting table by operating a moving mechanism that moves a relative position between the head unit, the inkjet head unit, and the three-dimensional modeling powder mounted on the mounting table. Distance control means for adjusting the distance in a direction perpendicular to the mounting table between the three-dimensional modeling powder and the inkjet head unit, and a specific range of the three-dimensional modeling powder placed on the mounting table The inkjet head unit discharges the modeling liquid so that the modeling liquid is discharged, and the moving mechanism moves the relative position in a direction parallel to the mounting table. And a discharge control means for controlling the work.

  The three-dimensional modeling apparatus according to the fourth aspect can generate a solid layer that is difficult to peel off. Therefore, it is possible to form a three-dimensional object having a desired shape.

It is the perspective view which looked at the three-dimensional modeling apparatus 1 from diagonally upward right. It is the II sectional view taken on the line in FIG. 3 is a block diagram showing an electrical configuration of the three-dimensional modeling apparatus 1. FIG. It is a flowchart of the modeling process which the three-dimensional modeling apparatus 1 performs.

  Hereinafter, an exemplary embodiment embodying the present invention will be described with reference to the drawings. The drawings to be referred to are used for explaining technical features that can be adopted by the present invention. The configuration of the device described in the drawings is not intended to be limited to that, but merely an illustrative example.

  The use of the three-dimensional modeling powder will be schematically described. The three-dimensional modeling powder is used together with a modeling liquid as a material for modeling a three-dimensional model. By mixing and solidifying the three-dimensional modeling powder and the modeling liquid, a three-dimensional modeled object having a desired shape can be modeled. Specifically, first, a flat layer is formed from the three-dimensionally shaped powder. When the modeling liquid is dropped from the three-dimensional modeling apparatus 1 (see FIGS. 1 to 3) onto the formed layer, the three-dimensional modeling powder is melted into the modeling liquid to produce a product, and the solid having this product A layer of material is produced. When the process of forming one solid layer is completed, a three-dimensionally shaped powder layer is further formed on the upper surface of the formed solid layer. A modeling liquid is dripped again from the three-dimensional modeling apparatus 1, and the layer of a solid substance is piled up. By repeating the above process and stacking the layers, the three-dimensional structure is formed into a desired shape.

  With reference to FIG. 1 and FIG. 2, the mechanical structure of the three-dimensional modeling apparatus 1 used for manufacture of a three-dimensional molded item is demonstrated. The lower left side of FIG. 1 is the front side of the three-dimensional modeling apparatus 1, and the upper right side of FIG. The right side of FIG. 1 is the right side of the three-dimensional modeling apparatus 1, and the left side of FIG.

  As shown in FIG. 1, the three-dimensional modeling apparatus 1 includes a rectangular parallelepiped base 2. The base 2 supports the entire three-dimensional modeling apparatus 1 and includes various mechanisms such as the transport unit 20. A box-shaped printing unit 3 is provided on the upper back side of the base 2. At the right end of the printing unit 3, four cartridges 4 that store the modeling liquid are arranged. Inside the cartridge 4 is housed a sealed pack that is degassed by sealing the modeling liquid. The sealed pack shrinks according to the amount of modeling liquid used, and no gas is mixed into the sealed pack, so that no bubbles are generated in the modeling liquid. Therefore, the three-dimensional modeling apparatus 1 can reliably discharge the modeling liquid. Each of the cartridges 4 is connected to each of four inkjet heads included in the inkjet head unit 5 (see FIG. 2) by a tube 6 and supplies a modeling liquid to each inkjet head. A rectangular opening 8 is formed in the lower part of the front wall 7 of the printing unit 3.

  The base 2 includes a transport unit 20 in the upper center. The conveyance unit 20 includes a placement belt 21 that is a wide timing belt on which the three-dimensionally shaped powder 25 is placed. On the front left side of the base 2, an operation unit 28 that receives various inputs from the operator is provided. An external I / F 29 for connecting the three-dimensional modeling apparatus 1 and an external device (for example, a personal computer) is provided at the rear side end of the right side surface of the base 2.

  As shown in FIG. 2, an inkjet head unit 5 is provided inside the printing unit 3. The inkjet head unit 5 holds four inkjet heads arranged in the left-right direction. A guide shaft 9 extending in the left-right direction passes through the inkjet head unit 5. Further, a timing belt 10 is connected to the inkjet head unit 5. The three-dimensional modeling apparatus 1 rotates the timing belt 10 by a head motor 35 (see FIG. 3) that is a step motor, thereby moving the inkjet head unit 5 in the left-right direction along the guide shaft 9, while placing the mounting belt. The modeling liquid can be ejected to the three-dimensional modeling powder 25 placed on 21.

  An inkjet head suction unit 12 is provided at the left end inside the printing unit 3. The inkjet head suction unit 12 includes four caps (not shown) and can be moved up and down. When the inkjet head unit 5 moves to the left end along the guide shaft 9, the inkjet head suction unit 12 moves up. Each of the four caps adheres to the lower part of each of the four inkjet heads provided in the inkjet head unit 5 and sucks the modeling liquid inside the inkjet head. As a result, the modeling liquid reaches a nozzle (not shown) at the lower end of the inkjet head. When the modeling liquid reaches the nozzle, the three-dimensional modeling apparatus 1 is in a state where the modeling liquid can be smoothly discharged. Further, the three-dimensional modeling apparatus 1 causes the cap of the inkjet head suction unit 12 to closely contact the inkjet head while the modeling liquid is not discharged. Therefore, the three-dimensional modeling apparatus 1 can prevent the three-dimensional modeling powder 25 from adhering to the inkjet head when the three-dimensional modeling powder 25 is placed on the placement belt 21.

  The transport unit 20 includes two pulleys 22 and 23 whose left-right direction is the direction of extension of the rotation shaft. The mounting belt 21 on which the three-dimensional modeling powder 25 is mounted has a predetermined width in the left-right direction. When the two pulleys 22 and 23 are rotated by a mounting belt motor 41 (see FIG. 3) which is a step motor, the mounting belt 21 rotates in the front-rear direction. The placement belt 21 extends from the front end portion of the base portion 2 to the rear end portion. Therefore, the three-dimensional modeling powder 25 placed on the placement belt 21 can move between the inside and the outside of the printing unit 3 through the opening 8. The three-dimensional modeling powder 25 is placed on the placement belt 21 outside the printing unit 3. When the three-dimensional modeling powder 25 is placed on the mounting belt 21, the three-dimensional modeling apparatus 1 allows the scattered three-dimensional modeling powder 25 to enter the inside of the printing unit 3 by the front wall 7 of the printing unit 3. Can be prevented.

  Furthermore, the transport unit 20 includes an elevating mechanism 42 (see FIG. 3) that elevates the placement belt 21 in the up and down direction. The three-dimensional modeling apparatus 1 moves the placement belt 21 downward each time the layer of the three-dimensional modeled object is stacked, so that the distance between the top surface of the three-dimensional modeled object and the three-dimensional modeled powder 25 and the inkjet head unit 5 is increased. Can be kept constant. Therefore, the three-dimensional modeling apparatus 1 can discharge the modeling liquid to a more accurate position. A control unit 30 that controls the operation of the three-dimensional modeling apparatus 1 is provided in the lower part on the back side inside the base unit 2.

  With reference to FIG. 3, the electrical configuration of the three-dimensional modeling apparatus 1 will be described. The three-dimensional modeling apparatus 1 includes a control unit 30, a printing unit 3, a transport unit 20, an operation unit 28, and an external I / F 29. Each unit is electrically connected by a bus 45.

  The control unit 30 includes a CPU 31, a RAM 32, and a ROM 33. The CPU 31 controls the three-dimensional modeling apparatus 1. The RAM 32 temporarily stores various information used in the control program. The ROM 33 stores a program for operating the three-dimensional modeling apparatus 1, an initial value, and the like.

  The printing unit 3 includes an inkjet head unit 5, a head motor 35, a discharge control circuit 36, and a suction control mechanism 37. The head motor 35 that is a step motor rotates in accordance with a signal from the CPU 31 to rotate the timing belt 10 (see FIG. 2), thereby moving the inkjet head unit 5 in the left-right direction. The ejection control circuit 36 controls ejection of the modeling liquid from each inkjet head provided in the inkjet head unit 5 in accordance with a signal from the CPU 31. The suction control mechanism 37 controls the lifting / lowering operation of the inkjet head suction unit 12 and the modeling liquid suction operation inside the inkjet head according to a signal from the CPU 31.

  The transport unit 20 includes a placement belt motor 41 and a lifting mechanism 42. The mounting belt motor 41, which is a step motor, rotates according to a signal from the CPU 31 to rotate the mounting belt 21, and conveys the three-dimensionally shaped powder 25. The elevating mechanism 42 elevates the placement belt 21 and adjusts the vertical distance between the upper surface of the three-dimensionally shaped powder 25 and the inkjet head unit 5.

  Although not illustrated, the three-dimensional modeling apparatus 1 includes a measuring mechanism that measures the three-dimensional modeling powder, a sieve into which the three-dimensional modeling powder measured by the measuring mechanism is charged, and a vibration mechanism that vibrates the sieve. The three-dimensional modeling apparatus 1 can evenly screen a certain amount of three-dimensional modeling powder onto the placement belt 21 by a measuring mechanism, a sieve, and a vibration mechanism. Further, the three-dimensional modeling apparatus 1 includes a squeegee (not shown) above the placement belt 21 in parallel with the placement belt 21. The three-dimensional modeling apparatus 1 adjusts the vertical position of the mounting belt 21 by the elevating mechanism 42 and rotates the mounting belt 21, thereby bringing the upper surface of the three-dimensional modeling powder into contact with the squeegee, and the upper surface of the powder. It can be flattened. The material of the squeegee is preferably a rust-resistant metal such as stainless steel or aluminum, or paper. Further, by using a squeegee made of a material that hardly generates static electricity, it is possible to prevent the upper surface of the powder from being rough due to the influence of static electricity or the like.

  With reference to FIG. 4, the modeling procedure (manufacturing method) of the three-dimensional molded item using the three-dimensional modeling apparatus 1 is demonstrated. The operator fills the cartridge 4 in advance with the modeling liquid and places it in the three-dimensional modeling apparatus 1. Next, the inkjet head suction unit 12 introduces the modeling liquid in the cartridge 4 to the nozzles of the inkjet head. Further, the operator causes the personal computer or the like to generate cross-sectional data of the three-dimensional structure from the three-dimensional data of the three-dimensional structure to be formed for each thickness of the solid layer. After performing the above processing, when an instruction to start modeling processing is input to the operation unit 28 of the three-dimensional modeling apparatus 1, the CPU 31 of the three-dimensional modeling apparatus 1 executes the modeling processing shown in FIG.

  First, the three-dimensional modeling apparatus 1 acquires cross-sectional data of the three-dimensional model from a personal computer or the like (S1). The weighing mechanism and the vibration mechanism are operated to supply the three-dimensionally shaped powder onto the placement medium (for example, cloth, plastic sheet, aluminum foil, etc.) laid on the placement belt 21 (S2). In addition, the three-dimensional modeling apparatus 1 which concerns on this Embodiment will complete | finish three-dimensional modeling powder by rotating the mounting belt 21 and making the upper surface of three-dimensional modeling powder contact a squeegee, after supply of three-dimensional modeling powder is complete | finished. Is flattened with a predetermined thickness.

  Next, the three-dimensional modeling apparatus 1 drives the head motor 35 and the mounting belt motor 41 based on the cross-section data of the lowest layer among one or a plurality of cross-section data about the three-dimensional model to be modeled, and three-dimensional modeling is performed. The molding liquid is discharged while moving the powder (S3). As a result, the three-dimensional modeling powder is dissolved in the modeling liquid to produce a product, and a solid layer containing this product is generated. The generated layer is the lowest layer of the three-dimensional structure. Here, the three-dimensional model | molding apparatus 1 may discharge a modeling liquid in the same location in multiple times. Specifically, the three-dimensional modeling apparatus 1 may change the number of ejections according to the thickness of the solid layer. In addition, it is desirable that the three-dimensional modeling apparatus 1 discharge more modeling liquid to a portion where the amount of modeling liquid discharged around is small. In this case, the three-dimensional modeling apparatus 1 can reliably model a modeled object having a fine shape such as a thin line or a point.

  If modeling of the uppermost layer is not completed among one or a plurality of solid layers (S4: NO), the three-dimensional modeling apparatus 1 lowers the mounting belt 21 by the thickness of one layer ( S5). The three-dimensional modeling apparatus 1 supplies the three-dimensional modeling powder to the upper surface of the already formed solid layer (S2). The three-dimensional modeling apparatus 1 discharges the modeling liquid based on the cross-sectional data of the layer one layer higher than the previously modeled layer (S3). By repeating the steps S2 to S5, the three-dimensional modeled object having the shape indicated by the three-dimensional data is sequentially modeled from the lower layer. Note that the number of solid layers to be modeled may be one. That is, the layers need not be stacked.

  When modeling of the uppermost layer is completed (S4: YES), the three-dimensional modeling apparatus 1 supplies the three-dimensional modeling powder again to the upper surface of the modeled solid (S6). As a result, the accuracy of modeling of the top surface of the three-dimensional model is improved, and it becomes easy to remove excess powder. Thus, the modeling process ends. Then, an operator takes out a three-dimensional molded item from powder. While sucking up dust with a dust collector, blow off excess powder with an air gun. With the above procedure, modeling of one three-dimensional model is completed.

  Next, the composition of the modeling liquid will be described. Although pure water can be used as a modeling liquid, it is desirable that the modeling liquid contains a thickening wetting agent using water as a solvent. The thickening wetting agent increases the viscosity of the modeling liquid and suppresses evaporation of water as a solvent. Since the modeling liquid contains the thickening and wetting agent, the modeling liquid can be easily ejected by inkjet, and the inkjet head is less likely to be clogged. Although various substances can be used for the thickening and wetting agent, it is desirable to use a dihydric or higher alcohol such as glycerin, diethylene glycol, and polyethylene glycol. Moreover, it is desirable that the modeling liquid contains a surfactant. If the surface tension of the modeling liquid is lowered by the surfactant, the three-dimensional modeling apparatus 1 can discharge the modeling liquid with high accuracy. Furthermore, the pH value of the modeling liquid is 7 or more, and desirably 9 or less. If the pH value of the modeling liquid is 7 or more, it is difficult to cause rusting in the ink jet head or the like. If the modeling liquid is weakly alkaline, the water-soluble polymer contained in the three-dimensional modeling powder is activated, so that a product generated by the three-dimensional modeling powder and the modeling liquid is easily generated. As a result, the three-dimensional model is smoothly modeled. Moreover, if the modeling liquid has a pH value of 9 or less, the water-soluble polymer is hardly hydrolyzed.

  Next, the composition of the three-dimensional modeling powder will be described. The three-dimensional modeling powder contains partially saponified polyvinyl alcohol. By using a three-dimensional modeling powder containing a partially saponified polyvinyl alcohol, it is possible to model a three-dimensional model having a higher strength than when using a three-dimensional modeling powder containing another water-soluble material as an adhesive. . The three-dimensional modeling powder can absorb the modeling liquid more easily by using partially saponified polyvinyl alcohol as compared to the case of using completely saponified polyvinyl alcohol. Therefore, a modeling process can be advanced smoothly. Further, since the layers of the three-dimensional modeled object are difficult to peel, a three-dimensional modeled object having a shape desired by the operator is modeled with high accuracy. The strength of the three-dimensional modeled object is also high. Further, when the three-dimensionally shaped powder is a completely saponified polyvinyl alcohol, there is a problem that the solid layer is easily warped and weak against pulling. On the other hand, when a three-dimensionally shaped powder containing partially saponified polyvinyl alcohol is used, the three-dimensionally shaped article that has been shaped hardly breaks even when pulled and the layer does not easily warp. In the present embodiment, polyvinyl alcohol having a saponification degree of 98 mol% or more is a complete saponification type, and polyvinyl alcohol having a saponification degree of 89 mol% or less is a partial saponification type. Details of these will be described later.

  In addition, when sucrose (sucrose) etc. are used for three-dimensional modeling powder, since solubility is too high, it is difficult to model a strong three-dimensional model. If sodium carboxymethyl cellulose or the like is used for the three-dimensional modeling powder, the dissolution rate is slow, so that modeling is difficult. Since sodium polyacrylate etc. expand | swell in the state which gelatinized and water-retained, it is difficult to shape | mold a three-dimensional molded item in a desired shape. From the above, it is desirable to adopt partially saponified polyvinyl alcohol in order to form a solid three-dimensional object that is difficult to peel off and has a desired shape.

  The particle size of the partially saponified polyvinyl alcohol is preferably 250 μm or less. By setting the particle diameter to 250 μm or less, for example, after flattening with a squeegee, the surface of the three-dimensional modeling powder becomes smooth. Therefore, when a layer of a three-dimensional model is laminated, the three-dimensional model can be modeled more accurately. In particular, if the particle diameter is 65 μm or less, the surface of the three-dimensionally shaped powder becomes smoother, which is more desirable.

  It is desirable that the three-dimensional modeling powder contains a filler (filler) that does not have an adhesive force. By containing the filler in the three-dimensional modeling powder, it is possible to suppress shrinkage of the three-dimensional modeled object due to the evaporation of water, so that the three-dimensional modeled object having the shape desired by the operator is accurately modeled. The filler may be inorganic or organic. It is desirable that the filler does not have water repellency. By including a filler having no water repellency in the three-dimensional modeling powder, the modeling liquid is hardly repelled by the three-dimensional modeling powder. As a result, a three-dimensional model can be modeled smoothly.

  Various materials can be used for the filler contained in the three-dimensional shaped powder. For example, it is desirable to use as the filler a material having low water repellency in the powder state, such as calcium carbonate, polyethylene terephthalate, polyester, talc, EVA (ethylene-vinyl acetate copolymer resin). In particular, calcium carbonate powder is more desirable because it is less likely to scatter than other materials, and it is difficult to cause clogging and contamination by adhering to an inkjet head or the like. The average particle size of the filler is desirably 9 μm or more and 40 μm or less. In this case, the error between the dimension desired by the operator and the dimension of the three-dimensional modeled object is within about 3%. Furthermore, if the average particle diameter of the filler is 9 μm or more and 25 μm or less, the dimensional error is within about 2%, which is more desirable.

In order to confirm the effects obtained by the three-dimensional modeling powder and the modeling procedure described above, the tests shown in Examples 1 to 5 were performed. Examples 1 to 5 will be described below.
[Example 1]
A test was conducted to confirm the effect of using partially saponified polyvinyl alcohol as a three-dimensionally shaped powder. In this test, one of three kinds of three-dimensional modeling powders and one of two kinds of modeling liquids were mixed to form five three-dimensional objects A to E. Observation and measurement of the properties of the three-dimensional modeled objects A to E were performed.

  The three-dimensionally shaped powder used in Example 1 is three types: “complete saponification (comparative example)”, “partial saponification A”, and “partial saponification B”. “Complete saponification (comparative example)” consists of polyvinyl alcohol (product name “Kuraray Poval”, grade 117S, manufactured by Kuraray Co., Ltd.) having a saponification degree of 98 to 99 mol% and a polymerization degree of 1700. “Partial saponification A” is made of polyvinyl alcohol having a saponification degree of 87 to 89 mol% and a polymerization degree of 500 (product name “Kuraray Poval”, grade 205S, manufactured by Kuraray Co., Ltd.). “Partial saponification B” is made of polyvinyl alcohol (product name “Kuraray Poval”, grade 224S, manufactured by Kuraray Co., Ltd.) having a saponification degree of 87 to 89 mol% and a polymerization degree of 2400. None of the three-dimensional shaped powders contains a filler. Polyvinyl alcohol has the property that when the degree of saponification is high, the solubility and hygroscopicity are low, and when the degree of polymerization is high, the water-soluble viscosity and the film strength are high. Moreover, the modeling liquid which consists only of pure water and the modeling liquid containing diethylene glycol (it describes as "DEG" in Table 1) were used for the modeling liquid.

  In Table 1, “delamination between layers” is a result of visual observation of whether or not adjacent solid layers are separated from each other. “Hardness” is a measurement result of hardness by a durometer. The durometer used is GS-701N manufactured by Teclock Co., Ltd. and conforms to JIS S6050. The “crack when dropping” is the presence or absence of cracking and deformation when the shaped three-dimensional model is thrown upward about 3 m and dropped. “Cut at the time of pulling” indicates whether or not the three-dimensional modeled object has been cut by hand.

  As shown in Table 1, it can be seen that by using polyvinyl alcohol as a three-dimensional modeling powder, a three-dimensional model that is resistant to drop impact is modeled. In addition, there was delamination between the three-dimensional objects A and B formed with the three-dimensional powder of “complete saponification (comparative example)”. On the other hand, there was no delamination between the three-dimensional molded objects C to E modeled by the three-dimensional molded powder of “partial saponification A” and “partial saponification B”. Therefore, it turns out that it becomes difficult to peel a solid layer by using partially saponified polyvinyl alcohol. If the degree of saponification is low, the three-dimensionally shaped powder dissolves smoothly, so that the solid layers are considered to adhere more strongly.

  The three-dimensional objects A and B formed with the three-dimensional powder of “complete saponification (comparative example)” were cut when pulled by hand. On the other hand, the three-dimensionally shaped objects C to E formed by the three-dimensionally shaped powder of “partial saponification A” and “partial saponification B” were not cut even when pulled. Therefore, it can be seen that by using partially saponified polyvinyl alcohol, it is possible to form a three-dimensional model that is difficult to cut even when pulled.

  If the modeling liquid to be used is the same, it turns out that the one using a partially saponified polyvinyl alcohol can model a hard three-dimensional modeled object rather than using a completely saponified polyvinyl alcohol. Moreover, it turns out that the direction which uses polyvinyl alcohol with a high polymerization degree can obtain a hard three-dimensional molded item from the result of the three-dimensional molded item C and D. FIG. In addition, the three-dimensional molded object modeled by the three-dimensional molded powder of “Partial saponification A” and “Partial saponification B” is compared with the three-dimensional molded article modeled by the three-dimensional molded powder of “complete saponification (comparative example)”. The solid layer was difficult to warp. When the degree of saponification is low, the three-dimensionally shaped powder is easy to adjust to water. When the three-dimensional modeling powder becomes familiar with water, the rate at which the water dries is decreased, and thus it is considered that the occurrence of warping is suppressed.

[Example 2]
A test for confirming the relationship between the particle diameter of polyvinyl alcohol and the smoothness of the upper surface of the flattened three-dimensionally shaped powder layer was conducted. The test contents will be described below.
(1) A polyvinyl alcohol having a saponification degree of 87 to 89 mol% and a polymerization degree of 2400 (made by Kuraray Co., Ltd., product name “Kuraray Poval”, grade 224S) is screened on a plane using a sieve having a predetermined opening diameter. .
(2) The top surface of the polyvinyl alcohol screened off is flattened using a squeegee having a length of 154 mm.
(3) Of the top surface of the flattened polyvinyl alcohol, 25 heights within a rectangular area of 30 mm × 110 mm are measured with a laser displacement meter (manufactured by Keyence Corporation, L-KG).
(4) The average value, standard deviation, the difference between the maximum value and the average value, and the difference between the minimum value and the average value are calculated from the results of 25 measurements. The difference between the standard deviation, the maximum value and the average value, and the difference between the minimum value and the average value is the smoothness (smoothness) of the upper surface of the layer of the three-dimensional modeling powder.
(5) The above (1) to (4) are repeated three times, and the average value of the calculated three standard deviations is calculated.
The above test was performed using three sieves having an opening diameter of Φ425 μm, an opening diameter of Φ250 μm, and an opening diameter of Φ63 μm. The results are shown in Table 2.

  When modeling a three-dimensional molded item, if one solid layer is too thick, the modeling liquid may not penetrate to the lower end of the layer. On the other hand, when the layer is too thin, when the upper surface of the layer is flattened by the squeegee, the squeegee is caught on the solid matter in the lower layer, causing problems such as misalignment, and accurate modeling becomes difficult. For the above reasons, the thickness of the layer is generally 0.1 mm to 0.01 inch (0.254 mm). When the thickness of the layer is 0.1 mm, if the standard deviation is close to 0.1 mm, a part of a certain layer may be located above the upper surface of the layer one level above. In this case, it becomes difficult to accurately stack the layers. In the test using a sieve having an opening diameter of Φ425 μm, the average standard deviation was 0.0861 mm, which was close to 0.1 mm. On the other hand, in the test using a sieve having an opening diameter of Φ250 μm, the average standard deviation was 0.0809 mm, and the surface became smoother. Therefore, the particle diameter of polyvinyl alcohol is desirably 250 μm or less. In the test using a sieve having an opening diameter of Φ63 μm, the smoothness was further greatly improved, and the average value of the standard deviation was 0.0519 mm. Accordingly, the particle diameter of polyvinyl alcohol is more preferably 63 μm or less.

[Example 3]
A test was performed to confirm the relationship between the filler and the shrinkage of the three-dimensional structure. In this test, a plurality of three-dimensionally shaped objects having the same shape were modeled using each of a plurality of three-dimensionally shaped powders A to G having different filler content conditions. The shrinkage rate of each three-dimensional model was calculated by measuring the dimension of each modeled three-dimensional model from the movement distance of the microscope stage and dividing the measured value by the target value of the dimension. The calculation results are shown in Table 3 below.

  The target values of the dimensions of the three-dimensional structure are 30 mm in the main operation direction, 25 mm in the sub-scanning direction, and 5 mm in thickness in the three-dimensional structure forming apparatus 1. All three-dimensional models contain the same modeling solution (69.79% by weight of pure water, 30% by weight of glycerin, 0.01% by weight of triethanolamine, and 0.2% by weight of nonionic surfactant) ). The three-dimensional modeling powder A is made of only polyvinyl alcohol. The three-dimensional shaped powders B to G contain 50% by weight of polyvinyl alcohol and 50% by weight of filler. The polyvinyl alcohols contained in the three-dimensional shaped powders A to G are all the same. Specifically, it is polyvinyl alcohol having a saponification degree of 87 to 89 mol% and a polymerization degree of 2400 (product name “Kuraray Poval”, grade 224S, manufactured by Kuraray Co., Ltd.). In Table 3, PET is polyethylene terephthalate (SK-RP-25CL / 7CL, manufactured by Seishin Enterprise Co., Ltd.). PES is a polyester that the inventor himself has researched and prototyped. EVA is an ethylene / vinyl acetate copolymer resin (manufactured by Seishin Co., Ltd., SK-EVA-40). A special grade reagent manufactured by Kanto Chemical Co., Inc. was used for calcium carbonate and talc.

  The three-dimensional modeled object modeled with the three-dimensional model powder A containing no filler has a shrinkage rate (dimensional error) of 3% or more. Further, the three-dimensional shaped powder B having an average particle diameter of the filler of 7 μm and the three-dimensional shaped powder G having the average particle diameter of the filler of 97 μm also had a shrinkage ratio of about 3% or more. On the other hand, when the three-dimensional shaped powders C to F having an average particle diameter of the filler of 9.2 to 40 μm were used, the shrinkage rate was within 3%. Therefore, it is desirable that the three-dimensional shaped powder contains a filler having an average particle diameter of 9 μm to 40 μm. Further, when the three-dimensionally shaped powders C to E having an average particle diameter of the filler of 9 μm to 25 μm were used, the shrinkage rate was within 2.1%. Therefore, it is more desirable that the three-dimensional shaped powder contains a filler having an average particle diameter of 9 μm to 25 μm. In the test range of Example 3, the filler material did not affect the shrinkage rate of the three-dimensional structure.

[Example 4]
A test was conducted to determine the material suitable for the filler based on the presence or absence of water repellency. In this test, a modeling liquid composed of pure water and a modeling liquid containing a thickening wetting agent were dropped onto a plurality of powdery materials. Whether the dropped modeling liquid permeates the material or remains as water droplets was visually observed. The observation results are shown in Table 4. In Table 4, “◯” indicates that the modeling liquid has permeated (the powdery material has no water repellency). “X” indicates that the modeling liquid remains as water droplets (the powdery material has water repellency). The middle of “◯” and “×” is indicated by “Δ”. In Table 4, PTFE is polytetrafluoroethylene (manufactured by Seishin Enterprise Co., Ltd., TFW-1000, particle size 10 μm). PE is polyethylene (manufactured by Seishin Co., Ltd., SK-PE-20, particle size 20 μm). PPW is propylene wax (manufactured by Seishin Enterprise Co., Ltd., PPW-5, particle size 5 μm). PET, EVA, calcium carbonate, and talc are the same as those used in Example 3.

  As described above, it is desirable that the filler has no water repellency. This is because if the filler has no water repellency, the modeling liquid is hardly repelled by the three-dimensional modeling powder, and a three-dimensional model can be modeled smoothly. PTFE, PE, and PPW were water-repellent with respect to both the modeling liquid composed of pure water and the modeling liquid containing the thickening wetting agent. In contrast, PET, EVA, calcium carbonate, and talc did not have water repellency with respect to the modeling liquid containing the thickening wetting agent. Therefore, PET, EVA, calcium carbonate, and talc are suitable as filler materials. Furthermore, calcium carbonate and talc also had poor water repellency against pure water. Thus, calcium carbonate and talc are more suitable as filler materials.

[Example 5]
A test was conducted to confirm that calcium carbonate suppresses the scattering of the three-dimensional shaped powder. In this test, the three-dimensional molded powder X consisting only of polyvinyl alcohol having a saponification degree of 87 to 89 mol% and a polymerization degree of 2400 (manufactured by Kuraray Co., Ltd., product name “Kuraray Poval”, grade 224S), and the above polyvinyl alcohol Three-dimensional modeling powder Y in which calcium carbonate was mixed at a weight ratio of 1: 1 was prepared. Using each three-dimensionally shaped powder, a test was performed according to the following procedure. (1) First, put a three-dimensionally shaped powder up to a 5 ml mark in a 50 ml tapping cell, and cover it. (2) Remove the three-dimensional modeling powder adhering above the 5 ml mark from the inner wall of the tapping cell. (3) A tapping cell is set in the multi tester MT-1001 manufactured by Seishin Corporation. (4) Tap 10 times in tapping mode (2 times / second). (5) After tapping, the three-dimensional shaped powder adhering to the inner wall of the tapping cell is observed.

  As a result of the test, the three-dimensional molded powder X consisting only of polyvinyl alcohol was adhered to the vicinity of the 17 ml surface line. On the other hand, the three-dimensional molded powder Y containing calcium carbonate was attached only to the vicinity of the 8 ml surface line. From the above, it was confirmed by tests that the use of calcium carbonate as a filler can suppress the scattering of the three-dimensionally shaped powder.

  In the above embodiment, the step of forming the layer by supplying the three-dimensionally shaped powder to the mounting belt 21 in S2 of FIG. 4 corresponds to the “layer forming step” of the present invention. The process of discharging the modeling liquid in S3 of FIG. 4 corresponds to the “generation process”. The mounting belt 21 corresponds to the “mounting table” of the present invention. The conveyance unit 20, the guide shaft 9 of the printing unit 3, the timing belt 10, and the head motor 35 correspond to the “movement mechanism” of the present invention. The CPU 31 that controls to lower the placement belt 21 in S5 of FIG. 4 functions as the “distance control means” of the present invention. The CPU 31 that performs control to discharge the modeling liquid while moving the three-dimensional modeling powder on the mounting belt 21 in S3 of FIG. 4 functions as the “discharge control unit” of the present invention.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the modeling procedure described with reference to FIG. 4 can be changed as appropriate. More specifically, after completion of the top layer modeling, the excess powder may be removed without supplying the three-dimensional modeling powder (S6). The three-dimensional modeling powder may contain substances other than partially saponified polyvinyl alcohol and filler.

  The process of supplying the three-dimensionally shaped powder to the mounting belt 21 may be performed by the operator himself. In this case, preferably, the operator arranges a jig for adjusting the thickness of the three-dimensional modeling powder on the mounting belt 21. For example, an operator may arrange two step-shaped jigs whose height for each step is a predetermined distance (for example, 2 mm) symmetrically so that the step portions face each other. In this case, the operator can arrange the three-dimensionally shaped powder with an accurate thickness and flatness by sliding the squeegee to a predetermined step portion of the two jigs in the flattening step described later. The configuration of the jig can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Three-dimensional modeling apparatus 5 Inkjet head part 9 Guide shaft 10 Timing belt 20 Conveying part 21 Mounting belt 22, 23 Pulley 25 Three-dimensional modeling powder 31 CPU
35 Head Motor 41 Mounting Belt Motor

Claims (7)

A layer forming step of forming a layer with a three-dimensional modeling powder containing a water-soluble polymer;
The production | generation process which produces | generates the layer which has a product produced when the said solid modeling powder melt | dissolves in the said modeling liquid by dripping the modeling liquid which uses water as a solvent to the said layer formed in the said layer formation process. A method for manufacturing a three-dimensional structure comprising:
The method for producing a three-dimensional structure, wherein the water-soluble polymer contains partially saponified polyvinyl alcohol.   The method for producing a three-dimensional structure according to claim 1, wherein a particle size of the partially saponified polyvinyl alcohol contained in the water-soluble polymer is 250 μm or less.   3. The method for producing a three-dimensional structure according to claim 1, wherein the three-dimensional structure powder contains an inorganic material or an organic material having an average particle diameter of 9 μm or more and 40 μm or less as a filler.   3. The method for producing a three-dimensional structure according to claim 1, wherein the three-dimensional structure powder contains calcium carbonate having an average particle diameter of 9 μm or more and 40 μm or less as a filler. A three-dimensional object formed by laminating a product formed from a three-dimensional modeling powder containing a water-soluble polymer and a modeling liquid containing water as a solvent,
The three-dimensional modeled product characterized in that the water-soluble polymer contains partially saponified polyvinyl alcohol. A three-dimensional modeling powder containing a water-soluble polymer and forming a layer of a three-dimensional modeled object by dropping a modeling liquid using water as a solvent and dissolving in the modeling liquid,
The three-dimensional molded powder characterized in that the water-soluble polymer contains partially saponified polyvinyl alcohol. A mounting table for mounting a three-dimensional modeling powder containing partially saponified polyvinyl alcohol as a water-soluble polymer;
An inkjet head part capable of discharging a modeling liquid using water as a solvent;
A moving mechanism for moving the relative position between the inkjet head unit and the three-dimensional modeling powder placed on the mounting table;
A distance control unit that adjusts a distance in a direction perpendicular to the mounting table between the three-dimensional modeling powder mounted on the mounting table and the inkjet head unit by operating the moving mechanism;
The movement of the inkjet head unit to discharge the modeling liquid and the moving mechanism to the mounting table so that the modeling liquid is discharged to a specific range of the three-dimensional modeling powder placed on the mounting table. A three-dimensional modeling apparatus comprising: discharge control means for controlling an operation of moving the relative position in a parallel direction.

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