KR20200088193A - Cement-based composition and additive manufacturing method for 3D printing architectural exterior finishing materials - Google Patents

Abstract

The present invention relates to a cement-based composition for 3D printing for manufacturing laminated architectural exterior panels and sculptures, which is capable of stably maintaining a shape when atypical 3D printing architectural exterior panels and sculptures are laminated, and a method for manufacturing the same. The cement-based composition for 3D printing for manufacturing laminated architectural exterior panels and sculptures comprises: 20-60 wt% of cement; 5-20 wt% of fly ash; 30-70 wt% of silica sand No. 8; 1-10 wt% of EVA powder resin; 0.5-3 wt% of methyl cellulose; 0.5-3 wt% of calcium formate powder; and 0.1-2 wt% of carboxyl fluidizing agent powder.

Description

Cement-based composition and additive manufacturing method for 3D printing architectural exterior finishing materials}

The present invention relates to a cement-based composition and a manufacturing method for 3D printing, in particular, a 3D printing cement-based composition for manufacturing a laminated architectural exterior panel and sculptures to stably maintain a shape when stacking atypical 3D-printed architectural exterior panels and structures, and It relates to a manufacturing method.

The 3D printing technology field in the construction field is divided into structural materials and interior/exterior materials, and it is also related to the material and composite material fields that make up it. 3D printing technology can be applied in various fields related to the building industry and changes the existing manufacturing process. It is recognized as a major technology that can be done. The structural material part of the 3D printing technology is made by mixing and extruding a material suitable for 3D printing, and the walls forming a structure are continuously stacked by stacking them one by one. In general, in the case of small materials, the supply of materials satisfying the additive manufacturing technology, design, economics, and productivity, and large materials are laminated by applying structural reinforcement to form a single structure.

The 3D printing material is classified according to the chemical composition, thermal and physical properties of the material, the principles of the 3D printing process technology, and the physical shape of the material. In general, in the case of small materials, it is necessary to develop a layered manufacturing technology that secures strength and economics because it lacks the concept of props and reinforcing materials for large materials. It is a situation in which an appropriate level of additive manufacturing technology has not been prepared.

Korean Patent Publication No. 2017-0141348 (December 26, 2017)

Accordingly, the present invention has been proposed to solve the above-mentioned problems in general, and the object of the present invention is to manufacture a stacked building exterior panel and a structure to maintain a stable shape when stacking atypical 3D printed building exterior panels and structures. It is to provide a cement-based composition for 3D printing and a manufacturing method.

In order to achieve the above object, the cement-based composition for 3D printing according to the technical idea of the present invention is for manufacturing a laminated architectural exterior panel and sculpture, 20-60% by weight of cement, 5-20% by weight of fly ash, and silica sand 8 Contains 30 to 70% by weight of powder and 1 to 10% by weight of EVA powder resin, 0.5 to 3% by weight of methyl cellulose, 0.5 to 3% by weight of calcium formate powder, and 0.1 to 2% by weight of carboxyl fluidizing agent powder It can be characterized by its technical configuration.

Here, the cement may be characterized by using a mixture of portland cement and white portland cement, or using white portland cement.

In addition, the fly ash may be characterized in that it is used by adding at least one of metakaolin and silica fume powder.

In addition, the fly ash may be characterized in that it is pulverized into fine powders for viscosity control and strength enhancement.

In addition, the silica sand may be characterized in that it is used for the control of the degree, characterized in that the pulverized into fine powder for viscosity control.

In addition, the EVA powder resin may be characterized in that it is used by mixing at least one of an aqueous polymer for cement admixture and a re-emulsifying powder resin.

Water is mixed with the cement-based composition for 3D printing of the present invention and then mixed to make a paste, and by using a 3D printer having a nozzle having a diameter of 3 to 10 mm, laminating layer by layer, a necessary building material can be made.

On the other hand, the method of manufacturing a cement-based composition for 3D printing of the present invention is 20-60% by weight of cement, 5-20% by weight of fly ash, 30-70% by weight of silica sand No. 8, and 1-10% by weight of EVA powder resin , Methyl cellulose 0.5 to 3% by weight, 0.5 to 3% by weight of calcium formate powder, 0.1 to 2% by weight of carboxylating agent powder is prepared by mixing it is characterized by its technical constitution.

The cement-based composition for 3D printing and a manufacturing method for manufacturing a laminated architectural exterior panel and sculpture according to the present invention can stably maintain a shape when laminating an amorphous 3D printed architectural exterior panel and sculpture.

The cement-based composition for 3D printing according to the present invention is a key element of the 4th industrial revolution, and because of its wide range of applications in relation to lamination manufacturing, it is possible to secure related new technologies and to increase domestic technical skills by developing and commercializing related products. You can expect to secure world-class leading technology by developing your own technology.

1 is a sample photo 3D printed in a lamination method using a cement-based composition for 3D printing according to an embodiment of the present invention
Figure 2 is a graph showing the raw material diameter size of the cement-based composition for 3D printing
3 is a graph comparing the fluidity of each test body of the cement-based composition for 3D printing
4 is a density comparison graph for each test body of the cement-based composition for 3D printing
5 is a comparative graph of compressive strength for each test body of the cement-based composition for 3D printing
Figures 6a to 6c is a comparative picture and flow value of each specimen of the cement-based composition through the flow experiment
7 is a comparative picture of each test body of the cement-based composition through a lamination experiment
8 is a graph comparing the fluidity of each test sample series of a cement-based composition for 3D printing.
9 is a graph showing the compressive strength of each test series of cement-based compositions for 3D printing.

The cement-based composition for 3D printing according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, it should be understood to include all modifications, equivalents, or substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals are used for similar components. In the accompanying drawings, the dimensions of the structures are enlarged than actual ones for the clarity of the present invention, or reduced in scale than actual ones in order to understand a schematic configuration.

Further, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. On the other hand, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

<Example>

The cement-based composition for 3D printing according to an embodiment of the present invention is for manufacturing a laminated architectural exterior panel and moldings, and is capable of stably maintaining a shape when stacking atypical 3D printed architectural exterior panels and moldings by a 3D printer.

To this end, the cement-based composition for 3D printing according to the embodiment of the present invention is 20-60% by weight of cement, 5-20% by weight of fly ash, 30-70% by weight of silica sand 8, and 1-10% by weight of EVA powder resin , Methyl cellulose 0.5 to 3% by weight, calcium formate powder 0.5 to 3% by weight, carboxyl fluidizing agent powder 0.1 to 2% by weight.

Here, the cement may be usually used by mixing Portland cement and white Portland cement, or white Portland cement. If the amount of the cement used is less than 20% by weight, the compressive strength is not exhibited, and durability is greatly reduced, and if it exceeds 60% by weight, it interferes with mixing of other ingredients in a sufficient amount.

The fly ash plays an important role in imparting fluidity to the composition, and in order to maximize it, it is preferable to use it by adding at least one of metakaolin and silica fume powder. The fly ash is preferably pulverized into fine powders for viscosity control and strength enhancement. If the mixing ratio of the fly ash is less than 5% by weight, fluidity at the time of manufacture decreases, and when it exceeds 20% by weight, strength may be lowered.

The silica sand 8 yarn has shrinkage when the mixing ratio is less than 40% by weight, and when it exceeds 70% by weight, it causes a decrease in strength and is not sufficiently mixed. The silica sand should be used as fine particles having an average particle diameter of 0.05 to 0.17 mm, and the coarse particles have a rough surface and are disadvantageous for lamination.

The S/C ratio was set to 1:1, and when used 1:1 or more, it is disadvantageous for mixing and kneading.

When the mixing ratio of the EVA powder is less than 1% by weight, durability decreases, and when it exceeds 10% by weight, strength decreases. The EVA powder resin is preferably used by mixing at least one of an aqueous polymer for cement mixing and a re-emulsifying powder resin.

The methylcellulose is used to increase the viscosity of the cement dough to make it advantageous for lamination. When the mixing ratio is less than 0.5% by weight, the viscosity of the dough is not greatly improved, and when it exceeds 3% by weight, the viscosity becomes excessively high, so that the dough This is not going well.

The calcium formate is a chemical admixture that promotes condensation of the cement paste and is included to control the setting time for lamination. If the mixing ratio of the calcium formate is less than 0.5% by weight, the setting time is not shortened well, and when it exceeds 3% by weight, it becomes difficult to knead the dough rapidly.

The carboxyl fluidizing agent is mixed to ensure the fluidity of the cement paste. When the mixing ratio of the carboxyl fluidizing agent is less than 0.1% by weight, the fluidity of the dough decreases, and extrusion is difficult. If it exceeds 2% by weight, the dough is released and material separation occurs.

In addition to the above main components, light weight hollow silica may be additionally mixed to maximize light weight. The lightweight hollow silica is preferably mixed with 20 to 80% by weight of the silica sand. If the light weight hollow silica is mixed to less than 20% of the silica sand, the effect of light weight reduction is negligible, and if it exceeds 80%, strength may be reduced.

In addition, 0.5 to 3% by weight of methyl cellulose for enhancing viscosity, 0.5 to 3% by weight of calcium formate powder for controlling setting time, and 0.1 to 2% by weight of carboxyl fluidizing agent powder for controlling fluidity are further mixed. desirable.

<Experimental Example>

After mixing water in the cement-based composition for 3D printing according to an embodiment of the present invention, mixing to make a paste, and laminating layer by layer using a 3D printer having a nozzle having a diameter of 3 to 10 mm, layer by layer as shown in FIG. I had a product to have. At this time, 450 g of cement, 50 g of fly ash, 500 g of silica sand, 20 g of methylcellulose, 5 g of calcium formate, 3 g of a carboxyl-based fluidizing agent, 45 g of ethylene vinyl acetate or 45 g of ethylene vinyl chloride, and 250 g of water and 250 g of water are used as a cement-based composition for 3D printing. Was prepared, it was confirmed that to maintain a stable shape when laminated by the composition thus prepared.

Subsequently, the results of confirming the characteristics expressed according to the composition of the ingredients for each test body will be described below. The composition of the ingredients according to each test subject is shown in Table 1. For the mixing of each component, a forced mortar mixer was used, and for the homogeneity of each component, it was produced by conducting pre-beaming.

Series W/C Cement Fly ash Silica sand EVA Thickener Super
plasticizer CEFM 50 50-0 50 450 50 500 - - - 50-1 445.5 4.5 - - 50-3 437.8 13.5 - - 50-5 427.5 22.5 - - 50-10 405 45.0 - - 50-0-1 450 - 2.3 - 50-0-2 450 - - 0.5

The cement used in this experiment was S port's normal Portland cement, and N's fly ash was used as the mixing material and silica sand No. 8 was used as the aggregate. Fly ash is used as an admixture for cement replacement. Its main components are silica (SiO ₂ ) and alumina (Al ₂ O ₃ ) to form a tight structure through a pozzolanic reaction, and it is excellent in light weight and chemical resistance. W-type EVA was used as the resin in the powder form. Methylcellulose was used as a thickener, and a carboxyl-based fluidizing agent was used as a super plasticizer. The diameter distribution of each component is shown in FIG. 2.

When comparing the fluidity of each test body, as shown in the fluidity graph of FIG. 3, only 50-0-1 with only thickeners without EVA powder resin or fluidizing agent lacked fluidity, and other specimens showed good fluidity. .

When comparing the density of each specimen, as shown in the density graph of FIG. 4, it was found that each specimen had a similar overall density, only 50-0-1 with only thickener without EVA powder resin or fluidizing agent. It has been shown to have a low density.

When comparing the compressive strength of each test body, as shown in the density graph of FIG. 5, when the mixing amount of the EVA powder resin was increased or the thickener was mixed, the compressive strength was relatively low. On the other hand, the proper amount of EVA powder resin and fluidizing agent not excessively appeared to increase the compressive strength.

Next, another experimental example will be described. For another experiment, the basic mixing ratio is shown in Table 2 below.

W/C C FA S Superplast
icizer Polymer Hardening
acceleration Thickener 0.4~0.6 900 100 1000 1% by weight or less 10% by weight or less 1-3% by weight or less 2% by weight or less

The mixed material was set to a content suitable for the characteristics of each material, the level of the basic material was set, and the mixing ratio used in the experiment is shown in Table 3 below. Corresponding to the cement-based composition for 3D printing according to an embodiment of the present invention was found to have a relatively suitable strength for lamination as a C series test body.

W/C No. Cement Fly ash Sand Superplast
icizer Polymer Thickener EVCL Series
A=0.50
B=0.60
C=0.55 0 450 50 500 - - - One 450 50 500 0.1% by weight - - 2 450 50 500 0.1% by weight - - 3 445.5 50 500 - 1% by weight - 4 437.5 50 500 - 3% by weight - 5 427.5 50 500 - 5% by weight - 6 405 50 500 - 10% by weight - 7 450 50 500 - - 0.5% by weight 8 450 50 500 - - 1% by weight

The blending was a basic experiment to investigate the applicability of 3D printing to the blended materials. A flow table was used to check the viscosity, and density and basic compressive strength experiments were performed to secure light weight. In a simple experiment to investigate the possibility of lamination, the lamination laboratory was performed by hand using a milking bag. The water-cement ratio of the formulation was determined at three levels, and the use of the binder was divided by number. The fluidizing agent and thickening agent were set at a level of 1% by weight or less, and were conducted at two levels in the experiment. The polymer was designed by mixing in 4 levels of 1, 3, 5, and 10% by weight.

The flow test was a basic experiment to find out the viscosity of each test body and was measured by the average diameter of the dough. The lamination was intended to confirm the lamination possibility by hand squeezing by a simple experiment using a milking bag. 6A to 6C show a comparison of a flow value and a photograph of each specimen during the flow test, and FIG. 7 is a photograph showing whether each specimen is stackable or not.

In the case of series A, it was judged that lamination was possible at a low water ratio, but in a simple experiment using hands, there was a limitation in hand weaving, which made it difficult to laminate.

As a result of the experiment, it was judged that the water ratio was 55%, and it was difficult to mix below 50%, and the fluidity increased as the water ratio increased and the amount of EVCL increased.

It was judged that it is suitable to use a fluidizing agent to improve the viscosity by adding a small amount of the fluidizing agent.

It was judged that the use of a thickener is difficult to mold and mold, and the flow is low, so the viscosity improvement is very effective, and it can be used by setting an appropriate amount according to the water ratio and miscible material.

EVCL and fluidizing agent form a lot of air bubbles in the dough, making the dough soft and low in viscosity, increasing the flow. In the case of thickeners and EVCLs, lamination is possible. EVCL has a smooth surface, soft dough, and thickeners, but the dough is thin. In the case, it was found that the surface was smooth and there was no sagging in the lower layer of the laminated test body, which was advantageous for lamination.

8 is a summary of comparison of flow values between series of test specimens. Regardless of the formulation, the increase in water increases the fluidity and the fluidity increases as the amount of EVCL increases.

9 shows a comparison of compressive strengths between series of test specimens. The compressive strength was highest at the water ratio of 55%, and the strength decreased as the content of EVCL increased. In the case of A formulation, the dough was not well formed, so it was found that the strength was lowered when there was no mixing material.

It was found that the viscosity of the thickening agent was difficult due to the viscosity, so that the strength was low, and the fluidizing agent was found to decrease the strength due to the large amount of air bubbles. The compressive strength is markedly lowered with the increase in the amount of EVCL, and when it is mixed with 5% or more, it is found that there is a limit to the strength expression.

Although the preferred embodiments of the present invention have been described above, the present invention can use various changes, modifications, and equivalents. It is clear that the present invention can be equally applied by appropriately modifying the above embodiments. Accordingly, the above description is not intended to limit the scope of the present invention as defined by the following claims.

Claims (12)

As a cement-based composition for 3D printing for the production of laminated building exterior panels and sculptures,
20~60% by weight of cement, 5~20% by weight of fly ash, 30~70% by weight of silica sand #8 and 1~10% by weight of EVA powder resin, 0.5~3% by weight of methyl cellulose, calcium formate powder Cement-based composition for 3D printing, characterized in that it contains 0.5 to 3% by weight, carboxyl fluidizing agent powder 0.1 to 2% by weight. According to claim 1,
The cement is a cement-based composition for 3D printing, which is usually used by mixing Portland cement and white Portland cement or using white Portland cement. According to claim 1,
The fly ash is a cement-based composition for 3D printing, characterized in that it is used by adding at least one of metakaolin and silica fume powder. According to claim 3,
The fly ash is a powder composition for 3D printing cement mixing, characterized in that it is pulverized into fine powders for viscosity control and strength enhancement. According to claim 1,
The silica sand is a cement-based composition for 3D printing, characterized in that it is used for controlling the degree, etc., characterized in that it is pulverized into fine powders for viscosity control. According to claim 1,
The EVA powder resin is a cement-based composition for 3D printing, characterized in that it is used by mixing at least one of an aqueous polymer for cement mixing and a re-emulsifying powder resin. Mixing water in the cement-based composition for 3D printing of any one of claims 1 to 6 and mixing to make a paste,
Building material characterized by manufacturing by layer by layer using a 3D printer having a nozzle having a diameter of 3 to 10 mm. As a method of manufacturing a cement-based composition for 3D printing for the production of laminated building exterior panels and sculptures,
20~60% by weight of cement, 5~20% by weight of fly ash, 30~70% by weight of silica sand #8 and 1~10% by weight of EVA powder resin, 0.5~3% by weight of methyl cellulose, calcium formate powder 0.5 to 3% by weight, a method for producing a cement-based composition for 3D printing, characterized in that it is prepared by mixing 0.1 to 2% by weight of carboxyl fluidizing agent powder. The method of claim 8,
The cement is a method of manufacturing a cement-based composition for 3D printing, which is usually used by mixing Portland cement and white Portland cement or using white Portland cement. The method of claim 8,
The fly ash is used by adding at least one of metakaolin and silica fume powder, and a method for preparing a powder composition for mixing cement for 3D printing, characterized in that it is pulverized into fine powders for viscosity control and strength improvement. The method of claim 8,
The silica sand is a method of manufacturing a cement-based composition for 3D printing, characterized in that it is used for the control of the degree, etc., characterized in that it is pulverized into fine powders for viscosity control. The method of claim 8,
The EVA powder resin is a method for producing a cement-based composition for 3D printing, characterized in that it is used by mixing at least one of an aqueous polymer for cement mixing and a re-emulsifying powder resin.

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