JP2013154615A - Solid-shaping apparatus, method for manufacturing solid-shaped article, shaping liquid for solid-shaping apparatus, and solid-shaping powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-shaping apparatus which improves moisture resistance of solid-shaping powder as well as watertightness of a solid-shaped article, a method for manufacturing the solid-shaped article, a shaping liquid for the solid-shaping apparatus, and the solid-shaping powder.SOLUTION: A solid-shaping apparatus supplies solid-shaping powder containing water-soluble polymer to a placing belt (S2). The solid-shaping apparatus discharges a shaping liquid from an inkjet head to the solid-shaping powder, thereby generating a layer having a product formed by reaction between the solid-shaping powder and the shaping liquid (S3). The layers are stacked to generate a solid-shaped article of a desired shape. The shaping liquid contains a thickening wetting agent suppressing evaporation of water content and increasing viscosity of the shaping liquid, surfactant, and adhesive. The solid-shaping powder contains no water-soluble adhesive.

Description

  The present invention relates to a three-dimensional modeling apparatus that forms a three-dimensional model by discharging a modeling liquid onto a three-dimensional modeling powder and curing, a manufacturing method for a three-dimensional model, a modeling liquid for a three-dimensional modeling apparatus, and a three-dimensional modeling powder. .

  2. Description of the Related Art Conventionally, a technique for modeling a three-dimensional object by mixing a three-dimensional modeling powder (hereinafter referred to as “three-dimensional modeling powder”) and a modeling liquid and curing is known (for example, patents). Reference 1). The three-dimensionally shaped powder described in Patent Document 1 includes an adhesive, a filler, and a fiber. The modeling liquid uses water as a solvent. When the modeling liquid is dropped from the inkjet head and the modeling liquid and the three-dimensional modeling powder are mixed with the three-dimensional modeling powder arranged flat, the adhesive contained in the three-dimensional modeling powder reacts. The reacted adhesives are bonded together to form a layer. By repeating the above process and stacking the layers, a three-dimensional object having a shape desired by the operator is formed.

Japanese Patent No. 3607300

  Since the conventional three-dimensional modeling powder disclosed in Patent Document 1 contains a water-soluble adhesive, the problem is that it absorbs moisture during storage of the three-dimensional modeling powder and is cured or deteriorated. There was a point. Moreover, there existed a problem that a three-dimensional molded item lacked water resistance.

  The present invention relates to a three-dimensional modeling apparatus, a three-dimensional model manufacturing method, a three-dimensional modeling apparatus, a three-dimensional modeling apparatus, and a three-dimensional modeling powder. The purpose is to provide a body.

  The three-dimensional modeling apparatus according to the first aspect of the present invention includes a mounting table for mounting a three-dimensional modeling powder containing calcined gypsum, and an inkjet head unit capable of discharging a modeling liquid containing an adhesive using water as a solvent. A moving mechanism for moving a relative position between the inkjet head unit and the three-dimensional modeling powder placed on the mounting table, and the three-dimensional mounted on the mounting table by operating the moving mechanism. Distance control means for adjusting the distance in the direction perpendicular to the mounting table between the modeling powder and the inkjet head unit, and the modeling within a specific range of the three-dimensional modeling powder placed on the mounting table Discharge control means for controlling the operation of discharging the modeling liquid by the inkjet head unit and the operation of moving the relative position in the direction parallel to the mounting table by the inkjet head unit so that the liquid is discharged; Provided, wherein the shaped solution containing an adhesive.

  In the three-dimensional model | molding apparatus which concerns on a 1st aspect, since the modeling liquid contains the adhesive agent, it is not necessary to make a three-dimensional model | molding powder contain an adhesive agent. Accordingly, it is possible to prevent the three-dimensionally shaped powder from absorbing moisture and curing or deteriorating during storage. Moreover, the water resistance of a three-dimensional molded item can be improved.

  The adhesive contained in the modeling liquid may be a dispersion type adhesive. By using a dispersion type adhesive as an adhesive contained in the modeling liquid, water resistance is improved after the three-dimensional model is cured.

  The modeling liquid may be contained in at least a transparent ink dropped onto the three-dimensional modeling powder. If a modeling liquid containing an adhesive is included in the transparent ink, the three-dimensional modeling powder can be cured by discharging the transparent ink from the inkjet head unit to the three-dimensional modeling powder.

  The main component of the three-dimensional shaped powder is the calcined gypsum, and a smaller amount of an inorganic compound than the calcined gypsum may be added to the three-dimensional shaped powder. The inorganic compound functions as a curing accelerator, the curing speed and hardness increase, and the water resistance of the three-dimensional structure immediately after modeling is improved. Also, so-called “bleeding” in which the three-dimensional shaped powder becomes larger than the target size can be reduced.

  The calcined gypsum may be alpha calcined gypsum. The curing speed and hardness increase, and the water resistance of the three-dimensional structure is improved.

  The three-dimensional shaped powder may contain a smaller amount of water repellent than the alpha-type calcined gypsum. The property of the three-dimensional modeled powder during storage is stabilized, and the water resistance of the three-dimensional modeled product is improved.

  The water repellent may be a metal soap. When the three-dimensional modeling powder contains metal soap as a water repellent, the fluidity of the three-dimensional modeling powder is improved, so that the three-dimensional modeling powder during storage can be prevented from being cured and improved in stability.

  The three-dimensional shaped powder may contain a smaller amount of beta-type calcined gypsum than the alpha-type calcined gypsum. When the beta-type calcined gypsum is contained, the amount of water necessary for curing is increased as compared with the alpha-type calcined gypsum alone, so that the stability of the three-dimensional shaped powder during storage is improved.

  The inorganic compound may be at least one of salts, sulfates, alums, nitrates, hydrogen sulfates, oxo salts, aluminates, and mineral acids. These function as curing accelerators, and are cured in a short time, so that the strength immediately after modeling is strong, and the water resistance is also improved as compared with the addition of the above substances.

  The modeling liquid may contain water, a thickening wetting agent that suppresses evaporation of the water and thickens the liquid, a surfactant, a pH adjuster, and the adhesive. In this case, water evaporation can be easily suppressed and the modeling liquid can be thickened. As a result, it is possible to prevent the modeling liquid from being dried and clogged by the inkjet head, and to discharge the modeling liquid from the inkjet head to the three-dimensional modeling powder with high accuracy.

  The manufacturing method of the three-dimensional molded item which concerns on the 2nd aspect of this invention is a layer formation process which forms a layer with the three-dimensional molded powder containing calcined gypsum, and water is added to the said layer formed in the said layer formation process. And a production step of producing a layer having a product produced by reacting the modeling liquid with the modeling liquid by discharging a modeling liquid as a solvent from an inkjet head. The modeling liquid contains an adhesive. In the manufacturing method of the three-dimensional model according to the second aspect, since the modeling liquid contains the adhesive, it is not necessary to include the adhesive in the three-dimensional model powder. Accordingly, it is possible to prevent the three-dimensionally shaped powder from absorbing moisture and curing or deteriorating during storage. Moreover, the water resistance of a three-dimensional molded item can be improved.

  The adhesive contained in the modeling liquid may be a dispersion type adhesive. By using a dispersion type adhesive as an adhesive contained in the modeling liquid, water resistance is improved after the three-dimensional model is cured.

  The modeling liquid for the three-dimensional modeling apparatus according to the third aspect is a three-dimensional model that forms a solid by discharging the modeling liquid from the inkjet head unit to the three-dimensional modeling powder containing calcined gypsum placed on the mounting table. A modeling liquid for a modeling apparatus, wherein the modeling liquid contains a thickening wetting agent, a surfactant, a pH adjuster, and an adhesive that use water as a solvent to suppress the evaporation of the water and increase the viscosity of the liquid. May be. In this case, since the modeling liquid contains the adhesive, it is not necessary to include the adhesive in the three-dimensional modeling powder. Accordingly, it is possible to prevent the three-dimensionally shaped powder from absorbing moisture and curing or deteriorating during storage. Moreover, the water resistance of a three-dimensional molded item can be improved. Moreover, evaporation of water can be easily suppressed and the modeling liquid can be thickened. As a result, it is possible to prevent the modeling liquid from being dried and clogged by the inkjet head, and to discharge the modeling liquid from the inkjet head to the three-dimensional modeling powder with high accuracy.

  The adhesive contained in the modeling liquid may be a dispersion type adhesive. By using a dispersion type adhesive as an adhesive contained in the modeling liquid, water resistance is improved after the three-dimensional model is cured.

  The three-dimensional modeling powder for the three-dimensional modeling apparatus according to the fourth aspect discharges a modeling liquid containing an adhesive from the inkjet head unit to the three-dimensional modeling powder containing calcined gypsum placed on the mounting table. The three-dimensional modeling powder for a three-dimensional modeling apparatus for forming a three-dimensional model, wherein the main component of the three-dimensional modeling powder is the calcined gypsum, and a small amount of an inorganic compound is added to the calcined gypsum. It is characterized by. The inorganic compound functions as a curing accelerator, the curing speed and hardness increase, and the water resistance of the three-dimensional structure immediately after modeling is improved. Further, it is possible to reduce the bleeding that the three-dimensional modeling powder becomes larger than the expected size.

  The calcined gypsum may be alpha calcined gypsum. The curing speed and hardness increase, and the water resistance of the three-dimensional structure is improved.

  The three-dimensional shaped powder may contain a smaller amount of water repellent than the alpha-type calcined gypsum. The property of the three-dimensional modeled powder during storage is stabilized, and the water resistance of the three-dimensional modeled product is improved.

  The water repellent may be a metal soap. If metal soap is contained as a water repellent in the three-dimensional model powder, the fluidity of the three-dimensional model powder is improved, so that it is possible to prevent hardening of the three-dimensional model powder during storage and improve stability.

  A small amount of beta-type calcined gypsum may be included in the three-dimensional shaped powder than the alpha-type calcined gypsum. When the beta-type calcined gypsum is contained, the amount of water necessary for curing is increased as compared with the alpha-type calcined gypsum alone, so that the stability of the three-dimensional shaped powder during storage is improved.

  The inorganic compound may be at least one of salts, sulfates, alums, nitrates, hydrogen sulfates, oxo salts, aluminates, and mineral acids. These function as curing accelerators, and are cured in a short time, so that the strength immediately after modeling is strong, and the water resistance is also improved as compared with the addition of the above substances.

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. It is a figure which shows the shape and dimension of the modeling test piece 100. FIG.

  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 uses of the modeling liquid and the three-dimensional modeling powder will be schematically described. The modeling liquid and the three-dimensional modeling powder are materials for modeling a three-dimensional model. The three-dimensional modeling apparatus 1 of the present embodiment drops a three-dimensional modeling powder onto a three-dimensional modeling powder that does not contain a water-soluble adhesive, and causes the three-dimensional modeling powder to react with the modeling liquid and cure the three-dimensional modeling object. Model.

  Moreover, the modeling liquid which concerns on this Embodiment contains the adhesive agent, and discharges modeling liquid to the three-dimensional modeling powder from the inkjet head part 5 of the three-dimensional modeling apparatus 1 (refer FIG. 1 to FIG. 3), and is solid. Perform modeling. An operator can easily obtain a solid layer of a desired shape by dropping the modeling liquid onto the layer of the three-dimensional modeling powder arranged flat using the three-dimensional modeling apparatus 1. 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 using the three-dimensional modeling apparatus 1, and the layer of a solid substance is piled up. By repeating the above process and stacking layers, a three-dimensional object having a shape desired by the operator is formed.

  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. 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 causes the scattered three-dimensional modeling powder 25 to enter the inside of the printing unit 3 and the front wall 7 of the printing unit 3. Can be prevented by.

  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. In addition to the squeegee, a rotating roller can be used.

  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 reacts with 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 uppermost modeling surface of the three-dimensional model is in the same condition as the buried part, and the accuracy and color of the entire model are uniformed. 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. The modeling liquid contains an adhesive, a thickening wetting agent, and a surfactant using water as a solvent. Furthermore, the modeling liquid contains a pH adjuster and has a pH value of 7 or more and 9 or less. The modeling liquid according to the present embodiment is colorless and transparent, and is different from general printing ink. The modeling liquid is at least contained in the transparent ink ejected from the inkjet head unit 5, but may be contained in other inks such as cyan, magenta, yellow, and black ejected from the inkjet head unit 5. . Hereinafter, each component will be described in detail.

  The adhesive contained in the modeling liquid will be described. As an example of the adhesive, a dispersion type adhesive (an aqueous dispersion (latex emulsion) adhesive) is used. This dispersion-type adhesive is initially a suspension aqueous solution in which a solid content of a polymer is polymerized in water. Latex adhesives when colloidal natural or synthetic rubber is the main component, emulsion adhesives where polymers that do not react with water are emulsified with protective colloids and can be dissolved in water Classified. In some cases, different polymer components may be mixed in order to impart characteristics, and the degree of freedom in designing physical properties is high. Although it is excellent in storability, when it is frozen, it decomposes and stops functioning. Although it adheres at room temperature but does not solidify sufficiently in a low-temperature environment, it becomes whitened, so work on the minimum film forming temperature is required. In the bonding process, as in the solution system, the solvent is evaporated and the solute is cured to bond. The characteristics are similar to those of the solution system. As an example of the dispersion type adhesive, polyvinyl alcohol, vinyl acetate, acrylic, EVA or the like can be used as an emulsion. As an example, the amount added to the modeling liquid is 3% by weight. In addition, the addition amount to the modeling liquid of a dispersion type adhesive agent has the desirable range of 1-30 weight%. According to the inventor's experimental results, if the dispersion type adhesive is not mixed with the modeling liquid in an amount of about 1% by weight or more, the effect as an adhesive does not appear. It will cause trouble.

  Next, the thickening wetting agent will be described. The thickening wetting agent increases the viscosity of the modeling liquid and suppresses evaporation of water as a solvent. If the characteristics of the inkjet head (head configuration, drive voltage, frequency, etc.) do not match the characteristics of the liquid to be ejected, it is difficult for the inkjet head to eject the liquid accurately. In particular, since a piezo-type ink jet head has a weak ejection force, it is highly necessary to adjust the viscosity of the modeling liquid to the characteristics of the ink jet head. The modeling liquid is discharged with high accuracy by the inkjet head by being thickened by the thickening and wetting agent. Also, if the solvent water evaporates quickly, the modeling liquid is easily solidified in the inkjet head, and the inkjet head is likely to be clogged. The modeling liquid can prevent clogging of the inkjet head by suppressing the evaporation of water by the thickening wetting agent. Therefore, the modeling liquid containing the thickening and wetting agent is suitable for ejection by the ink jet head. Furthermore, if the modeling liquid does not contain a thickening wetting agent, the shrinkage of the three-dimensional model increases due to evaporation of water. As a result, the shrinkage rate of the portion where the distance to the placement medium is large is larger than the portion attached to the placement medium such as cloth, and the three-dimensional shaped object of the shape desired by the operator is not formed. . A modeling liquid can suppress shrinkage | contraction of a three-dimensional molded item by containing a thickening wetting agent, and can model a three-dimensional molded item with sufficient precision. Moreover, when the modeling liquid contains a thickening wetting agent, the finishing treatment effect by the post-curing agent by the cyanoacrylate adhesive is improved.

  Although various substances can be used for the thickening and wetting agent, it is preferable to use a dihydric or higher alcohol. Specifically, it is preferable to use one or more dihydric or higher alcohols such as glycerin, diethylene glycol, and polyethylene glycol as the thickening wetting agent. In particular, it is more preferable to use at least one of glycerin and diethylene glycol as a thickening wetting agent. Since glycerin and diethylene glycol have a low vapor pressure, the effect of suppressing the evaporation of water (so-called wetting effect) can be obtained efficiently. Furthermore, since glycerin and diethylene glycol have low toxicity, the operator can safely handle the modeling liquid. Since glycerin and diethylene glycol can be used together with general-purpose resins such as vinyl chloride resin and polystyrene, materials for the three-dimensional modeling apparatus 1 and the like are not restricted.

  Since polyethylene glycol having a high degree of polymerization (for example, polyethylene glycol 600) has a melting point of about 20 ° C., it may be solid or liquid depending on the temperature environment. Therefore, polyethylene glycol having a high degree of polymerization is difficult to handle and may precipitate under low temperature conditions. Therefore, when polyethylene glycol is included as a thickening and wetting agent in the modeling liquid, it is desirable to use one having a low degree of polymerization (for example, polyethylene glycol 200). The modeling liquid can be easily thickened only by containing a small amount of polyethylene glycol.

  Further, as a thickening wetting agent, 2P = 2-pyrrolidone, NMP = N-methyl-2-pyrrolidone, DMI = 1,3-dimethyl-2-imidazolidinone, etc. can be used. That is, an organic solvent having a vapor pressure at 20 ° C. of 1 hPa or less and freely mixed with water can be used as the thickening wetting agent.

  When the dihydric or higher alcohol is used as the thickening wetting agent, the content of the thickening wetting agent is preferably 1% by weight or more and 50% by weight or less with respect to the entire modeling liquid. By setting the content of the dihydric or higher alcohol to 1% by weight or more, water evaporation can be easily suppressed and the modeling liquid can be thickened. By setting the content to 50% by weight or less, it is possible to prevent the evaporation of water from being excessively suppressed and the hardness of the shaped article from being significantly reduced.

  In addition, the viscosity of the printing ink used for printing using an inkjet head is generally about 2.5 mPa · s or more. Therefore, if the viscosity of the modeling liquid is set to about 2.5 mPa · s or more by the thickening and wetting agent, the modeling liquid can be discharged with high accuracy as in the case of the printing ink even if the printing inkjet head is used.

  The pH adjuster will be described. The pH adjuster is used to adjust the pH value of the modeling liquid. If the modeling liquid does not become acidic, rusting is unlikely to occur on the inkjet head. Specifically, it is desirable that the pH value of the modeling liquid is 7 or more. In addition, if the modeling liquid does not become excessively alkaline, the operator can handle the modeling liquid safely. The pH value of the modeling liquid is desirably 7 or more and 9 or less. Various substances can be used as the pH adjuster. In particular, it is desirable to use amines having low toxicity as a pH adjuster. For example, triethanolamine (2,2 ′, 2 ″ -nitrilotriethanol) can be used as a pH adjuster.

  The surfactant will be described. The surfactant is contained in order to reduce the surface tension of the modeling liquid. It is difficult to accurately discharge a liquid having a large surface tension to the inkjet head. Since the modeling liquid containing the surfactant has a smaller surface tension than the modeling liquid not containing the surfactant, it can be discharged from the inkjet head with higher accuracy. Furthermore, if the surface tension of the modeling liquid is low, the modeling liquid penetrates into the three-dimensional modeling powder more easily than when the surface tension is high. Therefore, the worker can smoothly advance the modeling process.

  Next, the composition of the three-dimensional modeling powder will be described. The three-dimensional modeling powder contains calcined gypsum as a main component and does not contain a water-soluble adhesive such as a water-soluble polymer. In this Embodiment, since modeling liquid contains the adhesive agent, it is not necessary to make a solid modeling powder contain an adhesive agent. Accordingly, it is possible to prevent the solid molding powder from absorbing moisture and curing or deteriorating during storage of the solid modeling powder. Moreover, the water resistance of a three-dimensional molded item can be improved. As calcined gypsum, commercially available alpha-type calcined gypsum is used as a main component, and the particle size of alpha-type calcined gypsum is particles that remain on a mesh having a sieve size of 25 μm to a mesh having a size of 100 μm. Alpha-type calcined gypsum increases the curing speed and hardness, and improves the water resistance of the three-dimensional structure.

  Further, as an example, a commercially available beta-type calcined gypsum is added in an amount of 30 weight percent to the three-dimensional shaped powder. The amount of beta-type calcined gypsum added to the three-dimensionally shaped powder is desirably in the range of 10 to 30% by weight. According to the inventor's experimental results, if the amount is less than 10% by weight, the effect of reducing bleeding is small, but if it exceeds 30% by weight, the effect of reducing bleeding is large but the strength decreases. As the particle size of the beta-type calcined gypsum, particles remaining on a sieve having a mesh size of 25 μm to a mesh size of 100 μm are used. In addition, the addition amount of beta-type calcined gypsum is made smaller than the content of alpha-type calcined gypsum. When beta-type calcined gypsum is added, the amount of water necessary for curing is increased as compared with the alpha-type calcined gypsum alone, so that the stability of the three-dimensional shaped powder during storage is improved.

  In addition, a small amount of an inorganic compound is added to the three-dimensional shaped powder as a hardening accelerator than calcined gypsum. As an example of the inorganic compound, salts, sulfates, alums, nitrates, hydrogen sulfates, oxo salts, aluminates, mineral acids and the like are added. As an example, 3 weight percent potassium sulfate is added to the three-dimensional shaped powder. The addition amount of the inorganic compound is preferably 1 to 5% by weight. These function as curing accelerators, and are cured in a short time, so that the strength immediately after modeling is strong, and the water resistance is also improved as compared with the addition of the above substances. Further, it is possible to prevent bleeding in which the three-dimensional modeling powder is larger than the expected size.

  In addition, a small amount of water repellent is added to the three-dimensional shaped powder compared to alpha-type calcined gypsum. Metal soap is used as an example of the water repellent. If metal soap is contained as a water repellent in the three-dimensional model powder, the fluidity of the three-dimensional model powder is improved, so that it is possible to prevent hardening of the three-dimensional model powder during storage and improve stability. As an example of the metal soap, a long chain fatty acid metal salt, Mg, Ca, Zn or the like can be used. As an example, 0.01 weight percent of zinc stearate is added to the three-dimensional shaped powder.

  Moreover, it is desirable that the three-dimensional shaped 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, the operator can smoothly model the three-dimensional model. For example, a material having a low water repellency in a powder state such as calcium carbonate, polyethylene terephthalate, polyester, talc, EVA (ethylene-vinyl acetate copolymer resin) may be used as the filler.

  Next, in order to confirm about the effect of a hardening accelerator, the test of Example 1 was done. Embodiment 1 will be described with reference to FIGS. In Example 1, using the three-dimensional modeling apparatus 1 having the above-described configuration, the modeling liquid is discharged from the inkjet head unit 5 onto the three-dimensional modeling powder, and a length target A: 80 mm and a width target B shown in FIG. : The modeling test piece 100 of 10 mm and thickness target C: 4mm was created. The modeling test piece 100 to which the hardening accelerator was added and the modeling test piece 100 which does not add a hardening accelerator were created.

  As the three-dimensional shaped powder, a commercially available alpha-type calcined gypsum was a main component, and a commercially available beta-type calcined gypsum was added as an example by 30 weight percent. Moreover, the particle | grain diameter of alpha type calcined gypsum and beta type calcined gypsum used the particle | grains which remain | survived under the mesh of a sieve 25 micrometers-100 micrometers. As a water repellent, 0.01 weight percent of zinc stearate was added to the three-dimensional shaped powder. As the curing accelerator, potassium sulfate added with 3 weight percent and those not added were used.

  The modeling liquid used the thing containing an adhesive agent, a thickening wetting agent, and surfactant by using water as a solvent. The modeling liquid contains a pH adjuster and has a pH value of 7 or more and 9 or less. As an adhesive, polyvinyl alcohol was added to the 10 weight percent modeling liquid. The measurement results are shown in Table 1.

  As shown in Table 1, when there was no addition of a hardening accelerator, the modeling liquid was discharged to the three-dimensional modeling powder. Immediately after modeling (0 minutes), the strength of the modeling test piece was insufficient, so the modeling test piece 100 was taken out from the three-dimensional modeling apparatus 1 and measured for dimensions 10 minutes after modeling. The modeling test piece 100 became length A: 86.20mm, width B: 17.30mm, and thickness C: 7.935mm. On the other hand, when the hardening accelerator is added, the modeling liquid is discharged to the three-dimensional modeling powder, and after modeling, the modeling test piece 100 is taken out from the three-dimensional modeling apparatus 1 immediately (0 minutes) to determine the dimensions. Measured. The modeling specimen 100 has a length A: 82.35 mm, a width B: 12.90 mm, a thickness C: 6.133 mm, and a modeling target length A: 80 mm, a width B: 10 mm, and a thickness C: 4 mm. Approaching the. Therefore, it was confirmed that when the addition of the curing accelerator was added, the modeling test piece 100 was cured in a short time, and the dimension was also close to the target dimension, and so-called “bleeding” that was larger than the target dimension could be reduced. . Moreover, when a hardening accelerator and metal soap were added, the modeling test piece 100 was taken out from the three-dimensional modeling apparatus 1 immediately (0 minutes), and the dimension was measured. The modeling test piece 100 has a length A: 81.05 mm, a width B: 11.60 mm, a thickness C: 5.094 mm, and a modeling target length A: 80 mm, a width B: 10 mm, and a thickness C: 4 mm. I got closer. It was confirmed that addition of metal soap can further reduce bleeding.

  In said embodiment, since modeling liquid contains the adhesive agent, solid modeling powder does not need to contain a water-soluble adhesive agent. Accordingly, it is possible to prevent the three-dimensionally shaped powder from absorbing moisture and curing or deteriorating during storage. Moreover, the water resistance of a three-dimensional molded item can be improved.

  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 gypsum forming the main component of the three-dimensional shaped powder may be anhydrous gypsum in addition to alpha-type calcined gypsum and beta-type calcined gypsum. Moreover, the modeling procedure demonstrated with reference to FIG. 4 can be changed suitably. More specifically, the powder may be removed without supplying the three-dimensionally shaped powder (S6) after the uppermost layer is finished. The modeling liquid may contain substances other than the thickening wetting agent, the surfactant, and the pH adjusting agent. The modeling liquids A to J produced in Example 1 above all contain a pH adjuster. However, the modeling liquid does not need to contain a pH adjusting agent as long as it has a desirable pH value (for example, 7 or more and 9 or less) in a state where it does not contain a pH adjusting agent.

  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, the operator may arrange two step-shaped jigs whose height for each step is a predetermined distance (for example, 0.2 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 100 Modeling Test Piece

Claims (20)

A mounting table for mounting a three-dimensional molding powder containing calcined gypsum;
An ink jet head part capable of discharging a modeling liquid containing an adhesive with 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 discharge control means for controlling an operation of moving the relative position in a parallel direction,
The three-dimensional modeling apparatus, wherein the modeling liquid contains an adhesive.   The three-dimensional modeling apparatus according to claim 1, wherein the adhesive contained in the modeling liquid is a dispersion-type adhesive.   The three-dimensional modeling apparatus according to claim 1, wherein the modeling liquid is contained in at least a transparent ink dropped onto the three-dimensional modeling powder.   The main component of the three-dimensional modeling powder is the calcined gypsum, and a smaller amount of an inorganic compound than the calcined gypsum is added to the three-dimensional modeling powder. 3D modeling equipment.   The three-dimensional modeling apparatus according to claim 1, wherein the calcined gypsum is alpha-type calcined gypsum.   The three-dimensional modeling apparatus according to claim 5, wherein the three-dimensional modeling powder contains a smaller amount of water repellent than the alpha-type calcined gypsum.   The three-dimensional modeling apparatus according to claim 6, wherein the water repellent is a metal soap.   The three-dimensional modeling apparatus according to any one of claims 5 to 7, wherein the three-dimensional modeling powder contains a smaller amount of beta-type calcined gypsum than the alpha-type calcined gypsum.   5. The three-dimensional modeling apparatus according to claim 4, wherein the inorganic compound is at least one of a salt, a sulfate, an alum, a nitrate, a hydrogen sulfate, an oxo salt, an aluminate, and a mineral acid.   2. The modeling liquid contains a thickening wetting agent, a surfactant, a pH adjusting agent, and the adhesive that suppress water evaporation and thicken the liquid using water as a solvent. The three-dimensional modeling apparatus in any one of -9. A layer forming step of forming a layer with a three-dimensional modeling powder containing calcined gypsum;
A layer having a product generated by reacting the three-dimensional modeling powder with the modeling liquid is generated by discharging a modeling liquid using water as a solvent from the inkjet head to the layer formed in the layer forming step. A method for manufacturing a three-dimensional structure,
The manufacturing method of the three-dimensional molded item characterized by the said modeling liquid containing the adhesive agent.   The manufacturing method of the three-dimensional molded item according to claim 11, wherein the adhesive contained in the modeling liquid is a dispersion type adhesive. For a three-dimensional modeling powder containing calcined gypsum placed on a mounting table, a modeling liquid is ejected from the inkjet head part to form a three-dimensional modeling apparatus,
The modeling liquid contains a thickening wetting agent, a surfactant, a pH adjuster, and an adhesive that suppress water evaporation and thicken the liquid using water as a solvent. Modeling liquid.   The modeling liquid for a three-dimensional modeling apparatus according to claim 13, wherein the adhesive contained in the modeling liquid is a dispersion type adhesive. It is a three-dimensional modeling powder for a three-dimensional modeling apparatus that forms a three-dimensional object by discharging a modeling liquid containing an adhesive from the inkjet head part to a three-dimensional modeling powder containing calcined gypsum placed on a mounting table. And
The three-dimensional modeling powder for a three-dimensional modeling apparatus is characterized in that the main component of the three-dimensional modeling powder is the calcined gypsum, and a small amount of an inorganic compound is added to the calcined gypsum.   The three-dimensional modeling powder for a three-dimensional modeling apparatus according to claim 15, wherein the calcined gypsum is alpha type calcined gypsum.   The three-dimensional modeling powder for a three-dimensional modeling apparatus according to claim 16, wherein the three-dimensional modeling powder contains a smaller amount of water repellent than the alpha-type calcined gypsum.   The three-dimensional modeling powder for a three-dimensional modeling apparatus according to claim 17, wherein the water repellent is a metal soap.   The three-dimensional modeling powder for a three-dimensional modeling apparatus according to any one of claims 16 to 18, wherein the three-dimensional modeling powder contains a smaller amount of beta type calcined gypsum than the alpha type calcined gypsum.   The inorganic compound is at least one of salts, sulfates, alums, nitrates, hydrogen sulfates, oxo salts, aluminates, and mineral acids. 3D modeling powder for 3D modeling equipment.

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