JP2023136832A - Molding method of molded object - Google Patents

Abstract

To provide a molding method of a molded object, which can prevent blockage due to curing of a hydraulic composition in an additive manufacturing device and ensure self-reliance until the hydraulic composition is cured.SOLUTION: A molding method of a molded object using a hydraulic composition for an additive manufacturing device includes: a cement composition preparing step of mixing cement with a ferrite phase ratio of 4.0 mass% or more as a value calculated by Borg's formula and water to obtain a cement composition 8; an accelerating agent supplying step of supplying an accelerating agent 9 in an amount of 0.2 to 5.0 pts.mass per 100 pts.mass of cement to the cement composition 8 in a nozzle 3 of an additive manufacturing device 1, immediately before extruding the cement composition 8; an extruding step of extruding the hydraulic composition 11 for the additive manufacturing device from the additive manufacturing device 1; a molding step of molding a molded object by using the extruded hydraulic composition 11 for the additive manufacturing device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for forming a shaped object.

In recent years, a photocurable resin is extruded from a nozzle onto the top surface of a lamination stand of an additive manufacturing device (3D printer) to form an uncured layered body designed in advance as a two-dimensional shape. The layered body is irradiated with light and cured to obtain a hardened layered body, and then the above-mentioned operations and similar operations are repeated on this hardened layered body to form and harden it layer by layer. BACKGROUND OF THE INVENTION A technique for finally obtaining a shaped object (for example, one having an elaborate three-dimensional shape) that is a laminate having a desired three-dimensional shape designed in advance as a three-dimensional shape has become widespread. This technology is called additive manufacturing technology.

Additive manufacturing techniques using various materials other than photocurable resins (eg, cement) have also been developed.
As a cement slurry discharging device useful for manufacturing a modeled object, for example, Patent Document 1 discloses a cement slurry discharging device having hydraulic properties, which includes a device main body and a device that can be attached to and detached from the device main body. A first container containing a cement-containing liquid containing cement, water, and an inorganic acid, and a first container that can be detachably attached to the main body of the device contain an ionic emulsion type thickener. a second container for accommodating an alkaline solution containing the cement, a mixer for mixing the cement-containing liquid and the alkaline solution to obtain the cement slurry, and a mixer for transferring the cement-containing liquid in the first container to the mixer. A first transfer means for transferring, a second transfer means for transferring the alkaline solution in the second container to the mixer, and a discharge port for discharging the cement slurry from the mixer. , a cement slurry dispensing device is described.

JP 2017-24979 Publication

When manufacturing objects made of cement composition using extrusion-type additive manufacturing equipment, molds and the like are usually not installed, so the cement composition is hardened after being extruded from the nozzle of the additive manufacturing equipment. Self-supporting properties (ability to maintain the shape even when a new cement composition is layered on top of the extruded cement composition) are required.
In order to maintain the self-sustainability of a cement composition until it hardens, a method is known in which an accelerating agent is added to a cement composition that has relatively excellent fluidity. However, cement compositions with excellent quick hardening properties are difficult to maintain fluidity within the additive manufacturing equipment before being extruded from the nozzle, and when the time required for modeling becomes long, There is a problem in that blockages occur in the conduits for pumping the cement composition of additive manufacturing equipment.
An object of the present invention is to provide a method for forming a shaped object that can prevent blockage due to curing of a hydraulic composition in an additive manufacturing device and ensure self-reliance until the hydraulic composition hardens. That's true.

As a result of intensive studies to solve the above problems, the inventors of the present invention have discovered a process for obtaining a cement composition by mixing cement with a ferrite phase ratio of 4.0% by mass or more and water, and a process for obtaining a cement composition. Immediately before extrusion, a step of supplying an accelerating agent in an amount of 0.2 to 5.0 parts by mass based on 100 parts by mass of cement to obtain a hydraulic composition; The present invention was completed based on the discovery that the above object can be achieved by a method for forming a shaped object, which includes a step of extruding the object from an additive manufacturing device, and a step of forming the object using the extruded hydraulic composition.
That is, the present invention provides the following [1] to [7].
[1] A method for creating a modeled object using a hydraulic composition for additive manufacturing equipment, the method comprising cement having a ferrite phase ratio of 4.0% by mass or more as calculated by Borg's formula, and water. a cement composition preparation step to obtain a cement composition; and immediately before extruding the cement composition, 0.2 parts per 100 parts by mass of the cement is added to the cement composition in the nozzle of the additive manufacturing device. a step of supplying an quick setting agent in an amount of ~5.0 parts by mass to obtain the hydraulic composition for additive manufacturing equipment; and extruding the hydraulic composition for additive manufacturing equipment from the additive manufacturing equipment. A method for shaping a shaped object, the method comprising: an extrusion step; and a shaping step of shaping the shaped article using the extruded hydraulic composition for an additive manufacturing device.

[2] In the above cement composition preparation step, an amount of inorganic powder (excluding cement) is further mixed in an amount of 2 to 150 parts by mass per 100 parts by mass of cement. A method for creating objects.
[3] The method for forming a shaped object according to [2] above, wherein the inorganic powder is one or more selected from silica fume, pulverized blast furnace slag, fly ash, pulverized limestone, and pulverized silica stone.
[4] In the cement composition preparation step, any of the above [1] to [3] further includes mixing fibers in an amount of 0.1 to 4.0 parts by mass with respect to 100 parts by mass of cement. Method of manufacturing the described object.
[5] Supplying the thickener to the cement composition in the nozzle so that the thickener ultimately becomes a material constituting the hydraulic composition for additive manufacturing equipment [1] to [ 4].
[6] The method for forming a shaped object according to [5] above, wherein the amount of the thickener is 0.01 to 2.0 parts by mass based on 100 parts by mass of the cement.
[7] The method for forming a shaped article according to [5] or [6], wherein the thickener is one or more types of thickeners selected from cellulose, acrylic, and glycol.

According to the method for shaping a shaped object of the present invention, it is possible to prevent blockage due to curing of the hydraulic composition within the additive manufacturing apparatus, and to ensure self-reliance until the hydraulic composition hardens.

FIG. 2 is a diagram illustrating an example of a part of the additive manufacturing apparatus used in the method for manufacturing a shaped object of the present invention, and is a sectional view showing a state in which a portion of the additive manufacturing apparatus including a nozzle is cut in the vertical direction.

The method for forming a modeled object of the present invention is a method for forming a model using a hydraulic composition for additive manufacturing equipment (hereinafter also simply referred to as "hydraulic composition"), and is calculated using the Borg formula. The cement composition is obtained by mixing cement with a ferrite phase (4CaO・Al ₂ O ₃・Fe ₂ O ₃ ; also referred to as "C ₄ AF") ratio of 4.0% by mass or more as a value, and water. In the cement composition preparation process for obtaining a product and immediately before extruding the cement composition, an amount of 0.2 to 5.0 parts by mass based on 100 parts by mass of cement is added to the cement composition in the nozzle of the additive manufacturing device. A quick setting agent supplying step of supplying an quick setting agent to obtain a hydraulic composition for additive manufacturing equipment; an extrusion step of extruding the hydraulic composition for additive manufacturing equipment from the additive manufacturing equipment; and an extruded hydraulic composition for additive manufacturing equipment. The method includes a modeling step of modeling a modeled object using the following method. Below, each process will be explained in detail.

[Cement composition preparation process]
This step is a step in which cement having a ferrite phase ratio of 4.0% by mass or more as calculated by Borg's formula and water are mixed to obtain a cement composition.
As the cement, it is possible to use a cement that has physical properties that can be used as a material for a modeled object when the modeled object is modeled using an additive manufacturing device. Examples of such cements are normal portland cement, early strength portland cement, moderate heat portland cement, low heat portland cement, white portland cement, super fast hardening cement, super early strength portland cement, blast furnace cement, fly ash cement, and alumina cement. , ecocement, etc. These may be used alone or in combination of two or more.

The proportion of the ferrite phase in the cement is 4.0% by mass or more, preferably 5.0% by mass or more, more preferably 5.5% by mass or more, even more preferably 6.0% by mass or more, still more preferably 8.0% by mass or more. It is 0% by mass or more, particularly preferably 9.5% by mass or more. If the above ratio is less than 4.0% by mass, the self-supporting properties of the hydraulic composition will decrease. Furthermore, clogging due to hardening of the hydraulic composition within the nozzle is likely to occur. Further, from the viewpoint of ease of manufacturing cement, etc., the above ratio is preferably 25.0% by mass or less, more preferably 20.0% by mass or less, particularly preferably 15.0% by mass or less.
The proportion of belite (2CaO.SiO ₂ ; also referred to as C ₂ S) in the cement is preferably 8.0 to 75.0% by mass, more preferably 9.0 to 70.0% by mass, particularly preferably is 10.0 to 65.0% by mass. If the above ratio is 8.0% by mass or more, the strength development of the hydraulic composition will be further improved. If the above ratio is 75.0% by mass or less, the self-supporting properties of the hydraulic composition will be further improved.

The proportion of alite (3CaO.SiO ₂ ; also referred to as C ₃ S) in the cement is preferably 15.0 to 85.0% by mass, from the viewpoint of strength development and fluidity of the hydraulic composition. It is preferably 20.0 to 80.0% by weight, particularly preferably 25.0 to 75.0% by weight.
The proportion of aluminate phase (3CaO.Al ₂ O ₃ ; also referred to as C ₃ A) in the cement is preferably 0.5 to 12.0% by mass, more preferably 1.0 to 10.0% by mass, Particularly preferred is 1.5 to 9.0% by mass. If the above ratio is 1.0% by mass or more, the strength development of the hydraulic composition will be further improved. If the above ratio is 12.0% by mass or less, the heat of hydration of the hydraulic composition can be lowered.

The proportions of alite, berite, aluminate phase, and ferrite phase in cement can be calculated using the following Borg formulas (1) to (4) based on the results of chemical analysis of cement. can.
(1) Alite (C ₃ S) = (4.07 x CaO) - (7.60 x SiO ₂ ) - (6.72 x Al ₂ O ₃ ) - (1.43 x Fe ₂ O ₃ ) - (2.85× _SO3 )
(2) Be-lite (C ₂ S) = (2.87 x SiO ₂ ) - (0.754 x C ₃ S)
(3) Aluminate phase (C ₃ A) = (2.65 x Al ₂ O ₃ ) - (1.69 x Fe ₂ O ₃ )
(4) Ferrite phase (C ₄ AF) = (3.04×Fe ₂ O ₃ )

Water is not particularly limited, and examples include tap water, recovered water specified in "JIS A 5308:2019 (Ready Mixed Concrete)", and the like.
The amount of water is determined such that the water-cement ratio is preferably 25-50%, more preferably 30-45%, particularly preferably 35-42%. If the ratio is 25% or more, the compressive strength of the shaped object can be further increased. If the ratio is 50% or less, the shaped object can be made more difficult to deform during the process of laminating the hydraulic composition.
Note that the water-cement ratio is the mass ratio of water and cement (water/cement) expressed as a percentage (%).

When preparing a cement composition, the mixing means for mixing each material is not particularly limited, and a mixer commonly used for mixing mortar and concrete can be used.
Specifically, a vertical mixer, a horizontal mixer, a Nauta mixer, a tilting mixer, a forced mixer, a biaxial mixer, etc. may be mentioned.
Examples of vertical mixers include "Hobart Mixer" manufactured by Hobart, "Henschel Mixer" manufactured by Henschel, and the like.
An example of a horizontal mixer is "Ledige Mixer" manufactured by Ledige.

In this process, from the viewpoint of further preventing blockage due to curing of the hydraulic composition in the additive manufacturing equipment and further improving the independence of the model made of the hydraulic composition, Inorganic powder may also be mixed.
Examples of the inorganic powder include silica fume, pulverized blast furnace slag, fly ash, pulverized limestone, and pulverized silica stone. These may be used alone or in combination of two or more.
Among them, fine limestone powder is used from the viewpoint of further improving the self-reliance of a model made of a hydraulic composition and further preventing blockage due to hardening of the cement composition or hydraulic composition in an additive manufacturing device. It is preferred to use both silica fume and silica fume.

The amount of the above-mentioned inorganic powder (if there are two or more types of inorganic powder, the total amount) is set to 100% of the cement from the viewpoint of further preventing clogging due to hardening of the cement composition or hydraulic composition in the additive manufacturing equipment. It is preferably 2 to 150 parts by weight, more preferably 3 to 120 parts by weight.
When the above-mentioned inorganic powder (hereinafter sometimes abbreviated as "inorganic powder") is silica fume, the amount of silica fume is preferably 2 to 30 parts by mass, more preferably 8 to 28 parts by mass, based on 100 parts by mass of cement. Parts by weight, particularly preferably 12 to 25 parts by weight. When the amount is 2 parts by mass or more, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented. If the amount is 30 parts by mass or less, the strength development of the hydraulic composition will be further improved.
When the inorganic powder is pulverized blast furnace slag powder, the amount of pulverized blast furnace slag powder is preferably 2 to 40 parts by mass, more preferably 8 to 38 parts by mass, particularly preferably 12 to 35 parts by mass, based on 100 parts by mass of cement. Part by mass. When the amount is 2 parts by mass or more, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented. If the amount is 40 parts by mass or less, shrinkage of the shaped object after curing can be reduced.

When the inorganic powder is fly ash, the amount of fly ash is preferably 2 to 40 parts by mass, more preferably 8 to 38 parts by mass, particularly preferably 12 to 35 parts by mass, based on 100 parts by mass of cement. . When the amount is 2 parts by mass or more, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented. If the amount is 40 parts by mass or less, the initial strength of the shaped object can be increased.
When the inorganic powder is limestone fine powder, the amount of limestone fine powder is preferably 2 to 150 parts by mass, more preferably 8 to 130 parts by mass, particularly preferably 40 to 110 parts by mass, based on 100 parts by mass of cement. It is. When the amount is 2 parts by mass or more, the self-supporting properties of the hydraulic composition can be further improved. When the amount is 150 parts by mass or less, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented.
When the inorganic powder is silica fine powder, the amount of silica fine powder is preferably 2 to 40 parts by mass, more preferably 8 to 38 parts by mass, particularly preferably 12 to 35 parts by mass, based on 100 parts by mass of cement. It is. If the amount is 2 parts by mass or more, the self-supporting properties of the hydraulic composition will be further improved. When the amount is 40 parts by mass or less, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented.

The Blaine specific surface area of the blast furnace slag powder, fly ash, and limestone powder is preferably 2,500 to 10,000 cm ² /g, more preferably 3,000 to 9,000 cm ² /g, and even more preferably 3, 100 to 8,500 cm ² /g, particularly preferably 3,200 to 8,000 cm ² /g. When the Blaine specific surface area is 2,500 cm ² /g or more, the strength development of the hydraulic composition is further improved. When the Blaine specific surface area is 10,000 cm ² /g or less, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented.
The BET specific surface area of silica fume and silica fine powder is preferably 5 to 40 m ² /g, more preferably 10 to 35 m ² /g, even more preferably 15 to 30 m ² /g, particularly preferably 18 to 25 m ² /g. be. When the BET specific surface area is 5 m ² /g or more, the strength development of the hydraulic composition is further improved. When the BET specific surface area is 40 m ² /g or less, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented.

In this step, from the viewpoint of further improving the self-sustainability of the hydraulic composition and further preventing clogging due to hardening of the cement composition or hydraulic composition in the additive manufacturing equipment, fibers may be further mixed. good.
Examples of fibers include glass fibers, metal fibers, organic fibers, carbon fibers, and the like. These may be used alone or in combination of two or more. Among these, glass fiber is preferred from the viewpoint of economy and compatibility with cement.
The shape and dimensions of the fibers are preferably such that the length is 0.1 mm or more and the aspect ratio (length/diameter) is 20 or more, and more preferably the length is 1 to 30 mm and the aspect ratio (length/diameter) is 20 or more. ) is 20 to 1,000, more preferably the length is 2 to 20 mm, and the aspect ratio (length/diameter) is 50 to 500, and even more preferably the length is 5 to 15 mm, and the aspect ratio is 50 to 500. (length/diameter) is 100 to 400.
If the fiber length is 0.1 mm or more, the self-supporting properties of the hydraulic composition can be further improved. Moreover, the strength (for example, bending strength) of the shaped article after curing can be increased. If the length is 30 mm or less, clogging in the additive manufacturing apparatus can be further prevented. In addition, fiber balls are less likely to form during kneading.
Further, if the aspect ratio (length/diameter) of the fibers is 20 or more, the number of fibers in the same blending amount (same volume) increases, and the self-sustainability of the hydraulic composition can be further improved. Moreover, the strength (for example, bending strength) of the shaped article after curing can be further improved. Further, when the ratio is 1,000 or less, the strength of the fiber itself is sufficient and it becomes difficult to break when subjected to tension.

The amount of fiber is preferably 0.1 to 4.0 parts by mass, more preferably 0.3 to 3.5 parts by mass, particularly preferably 0.8 to 2.5 parts by mass, based on 100 parts by mass of cement. It is. If the amount is 0.1 parts by mass or more, the self-supporting properties of the hydraulic composition can be further improved. Moreover, the strength (for example, bending strength) of the shaped article after curing can be increased. When the amount is 4.0 parts by mass or less, the fluidity of the cement composition or hydraulic composition is further improved, and clogging in the additive manufacturing apparatus can be further prevented.

[Quick setting agent mixing process]
This step is a step provided after the cement composition preparation step, and immediately before extruding the cement composition obtained in the cement composition preparation step, 100 mass of cement is added to the cement composition in the nozzle of the additive manufacturing device. This is a step in which a hydraulic composition (hydraulic composition for additive manufacturing equipment) is obtained by supplying a quick-setting agent in an amount of 0.2 to 5.0 parts by mass based on the total volume of the hydraulic composition.
Immediately before extruding the cement composition means immediately before the hydraulic composition for additive manufacturing equipment (mixture of cement composition and quick setting agent) is extruded from the tip of the nozzle of the additive manufacturing equipment (for example, within 7 seconds). means.
The above-mentioned supply varies depending on the diameter of the nozzle of the additive manufacturing device, the discharge speed (the speed at which the hydraulic composition is extruded), etc., but for example, it is preferable that the hydraulic composition is supplied before the hydraulic composition is extruded to the outside from the nozzle. is carried out for 0.5 to 30 seconds, more preferably 1 to 15 seconds, even more preferably 1.5 to 10 seconds, particularly preferably 2 to 5 seconds. If the above-mentioned supply is performed at least 0.5 seconds before the hydraulic composition is pushed out from the nozzle, the supplied quick-setting agent and cement composition can be pushed out from the nozzle. Accordingly, the components are mixed more uniformly in the flow path of the nozzle, and the self-sustainability of the hydraulic composition can be further improved. If the above-mentioned supply is performed within 30 seconds from the time when the hydraulic composition is extruded to the outside from the above-mentioned nozzle, clogging due to hardening of the hydraulic composition within the nozzle can be further prevented.
In addition, from the viewpoint of uniformly mixing the supplied quick-setting agent and the cement composition, a mixing means such as an in-line mixer, a stirring blade, etc. may be provided inside the nozzle.

Examples of quick setting agents include aluminum quick setting agents such as aluminum sulfate and aluminum silicate, aluminate quick setting agents, and calcium aluminate quick setting agents.
The amount of the quick setting agent is 0.2 to 5.0 parts by mass, preferably 0.8 to 4.5 parts by mass, more preferably 1.0 to 4.0 parts by mass, and more preferably 1.0 to 4.0 parts by mass, based on 100 parts by mass of cement. The amount is preferably 1.2 to 3.0 parts by weight, particularly preferably 1.5 to 2.0 parts by weight. If the amount is less than 0.2 parts by mass, the self-supporting properties of the hydraulic composition will decrease. If the amount exceeds 5.0 parts by mass, the hydraulic composition will harden within the nozzle of the additive manufacturing device, making clogging more likely. Furthermore, the self-supporting properties of the hydraulic composition may be reduced.

[Extrusion process]
This step is a step provided after the quick-setting agent mixing step, and is a step in which the hydraulic composition for additive manufacturing equipment obtained in the quick-setting agent mixing step is extruded from the additive manufacturing device.
[Modeling process]
This step is a step provided after the extrusion step, and is a step of modeling a shaped object using the hydraulic composition for additive manufacturing equipment extruded in the extrusion step.

In the present invention, a thickener may be supplied to the cement composition in the nozzle so that the thickener ultimately becomes a material constituting the hydraulic composition for additive manufacturing equipment. By supplying a thickener to the cement composition, it is possible to further improve the appearance of the shaped object by reducing voids on the surface of the shaped object formed by hardening the hydraulic composition.
The thickener may be supplied before the quick-setting agent is supplied to the cement composition, or it may be supplied when the quick-setting agent is supplied to the cement composition (in other words, when the cement composition and the quick-setting agent are A thickener may also be supplied at the same time.
Among these, from the viewpoint of further improving the appearance of the model by reducing the voids on the surface of the model formed by hardening the hydraulic composition, thickening is performed before the quick-setting agent is supplied to the cement composition. Preferably, the agent is provided. More specifically, in the quick-setting agent supply step, a method may be mentioned in which a thickener is supplied to a cement composition to obtain a mixture, and then an quick-setting agent is supplied to the mixture to obtain a hydraulic composition. It will be done. By supplying a thickener in the rapid setting agent supply step, clogging within the additive manufacturing apparatus can be prevented.
In addition, the thickener is preferably supplied in the additive manufacturing device before the quick-setting agent is supplied to the cement composition, from the viewpoint of further preventing clogging due to hardening of the cement composition or hydraulic composition. It is preferable to carry out the reaction for .5 to 30 seconds, more preferably for 1 to 15 seconds, particularly preferably for 2 to 10 seconds.

Examples of thickeners include (1) cellulose thickeners such as cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and derivatives thereof (e.g., hydroxypropyl methyl ether), (2) polyacrylamide, polyacrylic Acrylic thickeners such as acid esters and polyacrylates (e.g. sodium polyacrylate), (3) glycol thickeners such as polyoxyethylene polyoxypropylene glycol, (4) guar gum, xanthan gum, deutan gum, Examples include polysaccharide thickeners derived from natural materials such as welan gum, carrageenan, locust bean gum, tara gum, pectin, gellan gum, alginates (eg, sodium alginate), and derivatives thereof. These may be used alone or in combination of two or more.
Furthermore, different types of thickeners may be used depending on the purpose. For example, from the viewpoint of further improving the appearance of a model by reducing the voids on the surface of the model formed by curing the hydraulic composition, a cellulose-based thickener is preferred, and hydroxypropyl methylcellulose is more preferred. In addition, if a cellulose-based thickener is used when a naphthalene sulfonic acid-based water reducing agent is used, phenomena such as a decrease in fluidity, an abnormal increase in air volume, and a delay in condensation time may occur. In that case, it is preferable to use an acrylic thickener. Further, when it is desired to increase the viscosity from the viewpoint of pumpability, but when it is desired to suppress the stress during flow (to prevent blockage), it is preferable to use a glycol-based thickener.

The amount of the thickener is preferably determined based on 100 parts by mass of the cement, from the viewpoint of further improving the appearance of the shaped object by reducing the voids on the surface of the shaped object obtained by hardening the hydraulic composition. 0.01 to 2.0 parts by weight, more preferably 0.03 to 1.8 parts by weight, even more preferably 0.09 to 1.1 parts by weight, particularly preferably 0.10 to 1.0 parts by weight. .
Further, when the thickener is a liquid substance, the viscosity of the thickener is preferably 8,000 to 40,000 mPa·s, more preferably 10,000 to 38,000 Pa·s, and particularly preferably 12,000 mPa·s. ~20,000 Pa・s.

The cement composition preferably contains fine aggregate from the viewpoint of reducing the amount of heat generated during preparation of the cement composition.
Examples of the fine aggregate include silica sand, river sand, land sand, sea sand, crushed sand (for example, crushed sand made of limestone), and the like.
The amount of fine aggregate relative to 100 parts by mass of cement is preferably 5 to 1,000 parts by mass, more preferably 8 to 900 parts by mass, even more preferably 20 to 500 parts by mass, particularly preferably 50 to 200 parts by mass. .
When the amount is 5 parts by mass or more, the effect of reducing the calorific value during preparation of the cement composition becomes greater. When the amount is 1,000 parts by mass or less, the compressive strength etc. of the composition of the present invention after curing become greater.
A preferable example of the fine aggregate includes one containing 50% by mass or more of granules having a particle size within the range of 0.1 to 0.3 mm (for example, silica sand No. 7, silica sand No. 6). .

The cement composition may optionally include other materials that may be included.
Examples of other materials include cement dispersants, set retarders, set accelerators, coarse aggregates, and the like.
Examples of cement dispersants include polycarboxylic acid water reducing agents.
Examples of setting retarders include citric acid and succinic acid.
Examples of the setting accelerator include sodium sulfate and sodium thiosulfate.
Examples of the coarse aggregate include river gravel, land gravel, sea gravel, crushed stone (for example, crushed stone made of limestone), and the like. When the composition of the present invention contains coarse aggregate, it is mainly used for shaping relatively large construction structures having a simple structure.
Fine aggregate and optionally other materials are usually mixed with cement and water in the cement composition preparation process.

An example of a specific method of supplying an accelerating agent and a thickening agent in the method for forming a shaped object of the present invention will be specifically described below with reference to FIG. 1.
In the cement composition preparation process, the cement composition 8 prepared by the above-mentioned mixing means is, for example, charged into a material input hopper (not shown) of the additive manufacturing apparatus 1, and from the material input hopper is passed through a supply pipe. 2 to the nozzle 3 of the additive manufacturing device 1 using a squeeze pump, an in-line mixer, or the like. The supply pipe 2 is not particularly limited, and examples thereof include a hose (flexible), a PVC pipe, and the like.
A quick setting agent 9 is supplied to the cement composition 8 within the nozzle 3 . As a result, the obtained hydraulic composition 11 for an additive manufacturing device is extruded from the additive manufacturing device 1.
The first supply path 6 for supplying the quick-setting agent 9 is located downstream of the connection between the supply pipe 2 and the nozzle 3 in the direction in which the cement composition 8 is extruded (discharged). The cement composition 8 is communicated with a flow path for pushing out the cement composition 8 to the outside. Further, the second supply path 7 for supplying the thickener 10 is located upstream of the communication portion between the first supply path 6 and the nozzle 3 in the direction in which the cement composition 8 is extruded (discharged). The side (between the connection part between the supply pipe 2 and the nozzle 3 and the communication part between the first supply path 6 and the nozzle 3) communicates with a flow path for pushing out the cement composition 8 of the nozzle 3 to the outside. There is.
By configuring the members constituting the additive manufacturing device 1 in this manner, the thickener can be supplied to the cement composition before the quick-setting agent is supplied.
Specifically, immediately before the cement composition 8 is extruded, the thickener 10 contained in the second container 5 is supplied and mixed with the cement composition 8 through the second supply path 7. to join together. Next, the quick-setting agent 9 housed in the first container 4 passes through the first supply path 6 and is supplied and mixed (combined) with the cement composition 8 to form a hydraulic composition (cement). A hydraulic composition 11) for additive manufacturing equipment is prepared, which is a mixture of a composition, an accelerating agent, and a thickener. In FIG. 1, the quick-setting agent and thickener are liquid substances, but the quick-setting agent and thickener used in the present invention are not limited to liquid substances.

Next, based on the modeling data read by a control computer (not shown), the nozzle 3 is moved onto a lamination table (usually with a flat top surface) of the additive manufacturing device. While doing so, the hydraulic composition is extruded (discharged) from the nozzle 3 to form a two-dimensional layered body. Thereafter, a second layered body is formed on this layered body, and the same operation is repeated thereafter, so that a shaped article made of a laminate having a desired shape can finally be modeled.

The dimensions of the shaped object are, for example, 0.5 to 10 m in length, 0.2 to 5 m in width, and 0.2 to 5 m in height.
Examples of shaped objects include a walkable bridge, a cylindrical column, a bench for two people, and the like.
At the time of design, the target object is divided into two or more parts, and when the object is manufactured, each of these two or more parts is manufactured at the same time, and then the two or more manufactured parts are combined. You may also complete the desired model. In this case, the time required to produce the shaped object can be shortened.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.
[Materials used]
(1) Cement 1: Ordinary Portland cement, made by Taiheiyo Cement Co., Ltd. (2) Cement 2: Early-strength Portland cement, made by Taiheiyo Cement Co., Ltd. (3) Cement 3: Moderate heat Portland cement, made by Taiheiyo Cement Co., Ltd. (4) Cement 4: Manufactured by Taiheiyo Cement Co., Ltd., low-temperature Portland cement (5) Cement 5: Manufactured by Lafarge Holcim, cement (6) Fine aggregate; No. 7 silica sand, maximum particle size: 0.3 mm or less (7) Rapid setting agent; Aluminum-based rapid cement Binder, manufactured by Nippon Sika Co., Ltd., product name “Signit L53AF”
(8) Thickener 1: Hydroxypropyl methylcellulose, viscosity: 15,000 mPa・s, manufactured by Sansho Co., Ltd., trade name “NEOVISCO MC 150000”
(9) Thickener 2: Hydroxypropyl methyl cellulose, viscosity: 30,000 mPa・s, manufactured by Sansho Co., Ltd., trade name “NEOVISCO MC 30000”
(10) Thickener 3: Hydroxyethylcellulose, manufactured by Sansho Co., Ltd., trade name “SANHEC-HHT”
(11) Water; Tap water (12) Inorganic powder 1; Silica fume, BET specific surface area: 20 m ² /g, density: 2.33 g/cm ³
(13) Inorganic powder 2: Ground blast furnace slag powder, Blaine specific surface area: 3,200 cm ² /g, density: 3.01 g/cm ³ , specified in "JIS A 6206:2013 (ground blast furnace slag powder for concrete)" (14) Inorganic powder 3; fly ash, Blaine specific surface area: 4,600 cm ² /g, density: 2.20 g/cm ³ , "JIS A 6201:2015 (for concrete)" (15) Inorganic powder 4; Limestone fine powder, Blaine specific surface area: 8,000 cm ² /g, density: 2.73 g/cm ³
(16) Inorganic powder 5; silica fine powder, BET specific surface area: 20 m ² /g, density: 2.71 g/cm ³
(17) Fiber 1; glass fiber, diameter: 0.2 mm, length: 10 mm, aspect ratio: 200
(18) Fiber 2; synthetic fiber, vinylon fiber, diameter: 0.2 mm, length: 10 mm, aspect ratio: 200
Table 1 shows the proportions of alite, belite, aluminate phase, and ferrite phase in cements 1 to 5, calculated using the Borg formula.

[Examples 1 to 6, Comparative Examples 1 to 3]
Using a Hobart mixer, cement of the type shown in Table 2, water, and fine aggregate in the amount shown in Table 2 were kneaded to prepare a cement composition. Note that the water-cement ratio was 40%.
The additive manufacturing apparatus used had a gate-shaped frame with a height of 130 mm, a width of 100 mm, and a depth of 1200 mm, an extrusion nozzle with an inner diameter of 14 mm, a control computer, and a control panel. The prepared cement composition is put into the cartridge of the additive manufacturing device, and the hydraulic composition is extruded from the extrusion nozzle to perform additive manufacturing under the conditions of injection width 16 mm, layer thickness 8 mm, and lamination speed 30 mm/sec. I got it.
When extruding the hydraulic composition, an amount of the quick-setting agent shown in Table 2 was supplied and mixed with the cement composition in the nozzle using a tube. Note that after the quick-setting agent was supplied, it took about 3 seconds until the hydraulic composition for additive manufacturing equipment (a mixture of the cement composition and the quick-setting agent) was extruded from the nozzle.

The independence of the above model was evaluated. In the evaluation, when creating a square shaped object with a width of 10 cm x length of 40 cm x height of 40 cm, a first layer of layered material is first created, and then a second layer of layered material is placed on top of the layered material. , and then repeat the same operation until the stacking height is 40 to 38 cm while maintaining self-reliance, and the score is ``5'', and the stacking height is 35 cm or more and less than 38 cm. "4" if the stacking was successful, "3" if the stacking height was 30 cm or more and less than 35 cm, and "2" if the stacking height was 20 cm or more and less than 30 cm. A rating of "1" was given if the stacking height was 10 cm or more and less than 20 cm, or if the stacking height was less than 10 cm and the model collapsed.
In addition, occlusion within the additive manufacturing equipment was evaluated. The evaluation is "5" if the hydraulic composition is extruded from the nozzle and the lamination width (width of the shaped object made of the extruded hydraulic composition) secures the design value, and if the hydraulic composition is extruded from the nozzle. "4" means that the hydraulic composition can be extruded continuously without interruption, and the lamination width is shorter than the design value, but the reduction rate is 5% or less, and the hydraulic composition can be extruded continuously without interruption. The hard composition is extruded from the nozzle, and the lamination width is shorter than the design value, but the reduction rate is more than 5% and less than 10%, and the hydraulic composition is extruded continuously without interruption. "3" means that the hydraulic composition can be extruded from the nozzle, but "2" means that the extrusion of the hydraulic composition is interrupted and becomes discontinuous, and "2" means that the hydraulic composition is not extruded from the nozzle. was set as "1".
The results are shown in Table 2.

[Example 7]
Before supplying the quick-setting agent to the cement composition in the nozzle using a tube and mixing, thickener 1 is added to the cement composition in the nozzle using a tube (used for supplying the quick-setting agent). A shaped article was created in the same manner as in Example 1, except for supplying and mixing using a material different from the above. The amount of thickener was 0.6 parts by mass per 100 parts by mass of cement, and the thickener was added and mixed about 3 seconds before the quick setting agent was added and mixed.
The appearance of the surface of the shaped article (presence or absence of voids) after curing was visually evaluated.
The above evaluation is ``◎'' when no voids due to entrained air are observed on the surface layer of the model, ``〇'' when almost no voids due to entrained air are observed on the surface layer of the model, and ``◎'' when no voids due to entrained air are observed on the surface layer of the model. A case where voids due to entrained air were confirmed in the molded object was marked as "△", and a case where many voids caused by entrained air were confirmed on the surface layer of the model and the appearance was not excellent was marked as "x".

[Example 8]
The quick-setting agent is supplied and mixed into the cement composition in the nozzle using a tube, and at the same time, the thickener 1 is added to the cement composition in the nozzle using a tube (the one used to supply the quick-setting agent). A shaped article was created in the same manner as in Example 1, except for supplying and mixing using a material different from the above. The amount of thickener was 0.6 parts by mass per 100 parts by mass of cement. In the same manner as in Example 7, the appearance (presence or absence of voids) of the surface of the shaped article after curing was visually evaluated.
[Example 9]
After feeding and mixing the quick setting agent into the cement composition in the nozzle using a tube, thickener 1 is added to the cement composition in the nozzle using the tube (the one used to supply the quick setting agent). A shaped article was created in the same manner as in Example 1, except for supplying and mixing using a material different from the above. The amount of thickener was 0.6 parts by mass per 100 parts by mass of cement. Further, after the thickener was supplied and mixed, it took about 1 second until the hydraulic composition (mixture of cement composition and quick-setting agent) was extruded from the nozzle. In the same manner as in Example 7, the appearance (presence or absence of voids) of the surface of the shaped article after curing was visually evaluated.

[Example 10]
A shaped article was produced in the same manner as in Example 7, except that thickener 2 was used instead of thickener 1. The appearance of the surface of the shaped article (presence or absence of voids) after curing was visually evaluated.
[Example 11]
A shaped article was produced in the same manner as in Example 7, except that thickener 3 was used instead of thickener 1. The appearance of the surface of the shaped article (presence or absence of voids) after curing was visually evaluated.
The respective results are shown in Table 3.

[Example 12]
Eight types of objects with different amounts of thickener supplied were modeled in the same manner as in Example 7, except that the amount of thickener supplied per 100 parts by mass of cement was changed to the amount shown in Table 4. The appearance (presence or absence of voids) of the surface of each shaped article after curing was visually evaluated.
The results are shown in Table 4.
For Examples 7 to 12, the self-sustainability of the molded object and the occlusiveness within the additive manufacturing apparatus were evaluated in the same manner as Examples 1 to 6, and both were rated "4".

From Table 2, Comparative Examples 1 and 2 (those in which the proportion of ferrite phase in the cement is 3.0% by mass) and Comparative Example 3 (those in which no quick-setting agent is used) are either self-supporting or obstructive. While one of the evaluations was "1", in Examples 1 to 6, there were no evaluations of either independence or obstructiveness, and according to the modeling method of the present invention, , it can be seen that the self-reliance and occlusiveness can be improved.
From Examples 7 to 9 in Table 3, it is clear that according to the method (Example 7) of supplying and mixing the thickener before supplying and mixing the quick-setting agent, the appearance of the modeled object can be made excellent. I can do it.
Moreover, from Examples 7, 10 and 11, it can be seen that the appearance of the model of Example 7 using hydroxypropyl methylcellulose having a viscosity of 15,000 mPa·s is the best.
From Table 4, it can be seen that when the amount of thickener supplied is 0.1 to 0.9 parts by mass, the appearance of the shaped object is the best.

[Examples 13-24]
Using a Hobart mixer, Cement 1, fine aggregate, silica fume, and water in the amounts shown in Table 5 were kneaded to prepare a cement composition. A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 5.
From Table 5, in Examples 13 to 16 (in which the amount of water was 40 parts by mass and the amount of quick-setting agent was 2.5 parts by mass), the self-supporting evaluation was "4" and the occlusive evaluation was is "5", whereas in Examples 17 to 23 (the amount of water is 20 to 30 parts by mass and the amount of quick setting agent is 1.5 to 2.0 parts by mass), It can be seen that the evaluation of independence is "5" and the evaluation of obstructiveness is "4". In addition, in Example 24 (the amount of silica fume is 5 parts by mass, the amount of water is 20 parts by mass, and the amount of quick setting agent is 1.5 parts by mass), the evaluation of occlusiveness is "3. "Met.

[Examples 25-36]
Using a Hobart mixer, cement 1, fine aggregate, pulverized blast furnace slag powder (indicated as "blast furnace slag" in Table 6), and water were mixed in the amounts shown in Table 6 to prepare a cement composition. . A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 6.
From Table 6, in Examples 25 to 28 (in which the amount of water was 40 parts by mass and the amount of quick-setting agent was 2.8 parts by mass), the self-supporting evaluation was "4" and the occlusive evaluation was In Examples 29 to 32 (in which the amount of water was 30 parts by mass and the amount of quick-setting agent was 2.2 parts by mass), the self-supporting property was evaluated as "4", and the occlusion property was evaluated as "4". In Examples 33 to 36 (in which the amount of water is 20 parts by mass and the amount of quick setting agent is 1.7 parts by mass), the evaluation of self-supporting is "5". , it can be seen that the evaluation of obstructiveness is "4".

[Examples 37-48]
A cement composition was prepared by kneading Cement 1, fine aggregate, fly ash, and water in the amounts shown in Table 7 using a Hobart mixer. A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 7.
From Table 7, in Examples 37 to 40 (in which the amount of water was 40 parts by mass and the amount of quick-setting agent was 2.6 parts by mass), the self-supporting evaluation was "4" and the occlusive evaluation was In Examples 41 to 44 (in which the amount of water is 30 parts by mass and the amount of quick setting agent is 2.1 parts by mass), the self-supporting evaluation is "4" and the blockage is In Examples 45 to 48 (in which the amount of water is 20 parts by mass and the amount of quick-setting agent is 1.6 parts by mass), the evaluation of self-supporting property is "5". ”, and the evaluation of obstructiveness was “4”.

[Examples 49-60]
A cement composition was prepared by kneading Cement 1, fine aggregate, fine limestone powder, and water in the amounts shown in Table 8 using a Hobart mixer. A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 8.
From the comparison of Examples 49 to 52 and Examples 53 to 56 in Table 8, it can be seen that when the amount of limestone powder is large, the self-sustainability tends to improve, and when the amount of limestone powder is small, the occlusion property tends to improve. I understand that.

[Examples 61 to 68]
A cement composition was prepared by kneading Cement 1, fine aggregate, the types of fibers shown in Table 9, and water in the amounts shown in Table 9 using a Hobart mixer. A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 9.
From the comparison of Examples 61 to 64 and Examples 65 to 68 in Table 9, it can be seen that when the amount of fibers is large, the self-reliance tends to improve, and when the amount of fibers is small, the occlusion property tends to improve. Recognize.

[Examples 69-80]
Using a Hobart mixer, Cement 1, fine aggregate, fine silica stone powder, and water were kneaded in the amounts shown in Table 10 to prepare a cement composition. A shaped object was obtained in the same manner as in Example 1 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 1. The results are shown in Table 10.
From the comparison of Examples 69 to 80 in Table 10, it can be seen that when the amount of water is large, the occlusion property tends to improve, and when the amount of water is small, the self-reliance tends to improve.

[Examples 81 to 103]
A cement composition was prepared by kneading the types and amounts of materials shown in Table 11 (excluding quick-setting agents and thickeners) using a Hobart mixer. A shaped object was obtained in the same manner as in Example 7 except that the obtained cement composition was used. The independence of the above-mentioned shaped object and the obstructiveness of the additive manufacturing apparatus were evaluated in the same manner as in Example 7. The results are shown in Table 11.

From Table 11, in Examples 81, 82, 97, 98, 101, and 102 (containing limestone powder, silica fume, and fibers, and the amount of silica fume being 10 to 15 parts by mass), self-supporting and obstructive It can be seen that both evaluations are "5".

1 Additive manufacturing device 2 Supply pipe 3 Nozzle 4 First container 5 Second container 6 First supply channel 7 Second supply channel 8 Cement composition 9 Rapid setting agent 10 Thickener 11 Hydraulic composition for additive manufacturing device thing

Claims (7)

A method for shaping a shaped object using a hydraulic composition for additive manufacturing equipment, the method comprising:
A cement composition preparation step of obtaining a cement composition by mixing cement with a ferrite phase ratio of 4.0% by mass or more as calculated by Borg's formula, and water;
Immediately before extruding the cement composition, an accelerating agent is supplied to the cement composition in the nozzle of the additive manufacturing device in an amount of 0.2 to 5.0 parts by mass based on 100 parts by mass of the cement. , a step of supplying an quick-setting agent to obtain the hydraulic composition for the additive manufacturing device;
an extrusion step of extruding the hydraulic composition for additive manufacturing equipment from the additive manufacturing equipment;
A method for shaping a shaped article, comprising the step of shaping the shaped article using the extruded hydraulic composition for an additive manufacturing device. The shaping of the shaped object according to claim 1, wherein in the cement composition preparation step, an amount of inorganic powder (excluding cement) is further mixed in an amount of 2 to 150 parts by mass with respect to 100 parts by mass of cement. Method. 3. The method for forming a shaped object according to claim 2, wherein the inorganic powder is one or more selected from silica fume, pulverized blast furnace slag, fly ash, pulverized limestone, and pulverized silica stone. The shaped article according to any one of claims 1 to 3, wherein in the cement composition preparation step, fibers are further mixed in an amount of 0.1 to 4.0 parts by mass based on 100 parts by mass of cement. modeling method. Any one of claims 1 to 4, wherein the thickener is supplied to the cement composition in the nozzle so that the thickener ultimately becomes a material constituting the hydraulic composition for additive manufacturing equipment. The method for manufacturing the modeled object described in Section 1. 6. The method for forming a shaped object according to claim 5, wherein the amount of the thickener is 0.01 to 2.0 parts by mass based on 100 parts by mass of the cement. 7. The method for forming a shaped object according to claim 5, wherein the thickener is one or more types of thickeners selected from cellulose, acrylic, and glycol.

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