3D 프린터용 점토의 조성에 관한 연구

최응한,강영탁,권다은,박예린,최경수 한국도자학회 2021 한국도자학연구 Vol.18 No.3

As the patents related to 3D printers expired in 2009, demand for 3D printers has exploded along with their development. Accordingly for this, FDM-type 3D printers can now be easily purchased and operated by anyone who is interested. The LDM-type 3D printer that prints clay directly is a printer that does not use filament as a material, but puts moderately well-kneaded clay into a cylinder and outputs and stacks the clay. There is no significant difference from conventional filament 3D printers in that the drawing file made of stl (StereoLithography) file is converted into g_code through a slice program and the 3D printer moves according to this converted coordinate value to complete the output, but since clay is used as a material, there is a big difference between the driving method of moving clay from the cylinder to the nozzle through the tube and the slicing setting value of extruding clay. There is no company that develops and produces this clay 3D printer in Korea yet, but many interested craftsmen have already imported and used the clay 3D printer from abroad. However, due to insufficient research on clay, the main material, expensive printers cannot be used properly. Therefore, in this paper, the composition ratio of the two types of clay, which is the most used in Korea, was studied so that anyone could use it in a clay 3D printer. As a research method, we tried to find the most optimal clay composition ratio through an experiment in which liquids such as ethanol, sodium silicate, and glycerin are added in addition to the moisture that clay has already, and powders such as alumina and chamotte. In addition, we tried to clarify in detail what role each added material played in the composition of clay. In conclusion, the most ideal composition ratio of clay for a 3D printer is not too hard when filling the cylinder with clay, so it should minimize the generation of bubbles, it should move smoothly from the cylinder through the tube to the nozzle, and not too muddy or sticky when it is being extruded. In addition to the composition ratio of the clay, many factors such as the slicing setting value, the type and leveling of the printer bed, and the shape of the nozzle acted as variables. 2009년 3D프린터에 관련된 특허가 만료됨으로써 그 개발과 함께 수요가 폭발적으로 증가했으며 이 에 따라 FDM방식의 3D프린터는 이제 누구나 관심만 있다면 손쉽게 구매와 운용이 가능하게 되었다. 점토를 바로 출력하는 LDM방식의 3D프린터는 필라멘트를 소재로 사용하는 것이 아닌 적당히 잘 반죽 된 점토를 실린더에 넣어 이 점토를 출력, 적층하는 프린터이다. stl(StereoLithography)확장자로 만들어 진 도면파일은 슬라이스 프로그램을 통해 g_code로 변환되고 3D프린터는 이 변환된 좌표값대로 움직 이면서 출력물을 완성하게 된다는 점에서는 기존의 필라멘트 3D프린터와 큰 차이가 없으나 점토를 재 료로 하기 때문에 점토를 실린더에서 튜브를 통해 노즐로 이동시키는 구동방식과 점토를 압출시키는 슬라이싱 설정값에서는 큰 차이가 있다. 아직 국내에서는 이 점토용 3D프린터를 개발, 생산하는 업체 가 없지만 많은 관심있는 공예가들은 이미 해외에서 점토용 3D프린터를 수입하여 사용하고 있다. 하지 만 주재료인 점토에 대한 연구가 미흡하여 고가의 프린터를 제대로 활용하지 못하고 있는 실정이다. 이에 본 논문에서는 국내에서 가장 많이 사용되고 있는 두 종류의 점토를 누구나 점토용 3D프린터 에 활용할 수 있도록 그 조성비를 연구하고자 하였다. 연구방법으로는 기본적으로 점토가 가지고 있는 수분외에 에탄올과 규산소다 그리고 글리세린 등의 액체류를 첨가하는 방식과 알루미나와 샤모트 등의 분말류를 첨가하는 실험을 통해 가장 최적의 점토 조성비를 찾고자 했다. 또한 첨가한 각각의 재료가 점토의 조성에서 어떤 역할을 했는지 상세히 밝히고자 노력하였다. 결론적으로, 3D프린터에 가장 이상적인 점토의 조성비는, 실린더에 점토를 채울 때는 너무 단단하지않아 기포발생을 최소화해야 하고 실린더에서 튜브를 통과해 노즐까지는 부드럽게 이동해야 하며, 노즐 에서압출되어적층될때는너무질거나끈적이지않아야했다. 또한점토의조성비율외에도슬라이 싱 설정값, 프린터베드의 종류와 레벨링, 그리고 노즐의 생김새 등 많은 요인이 변수로 작용하였다.

황토의 Microcystis spp. 제거효율 및 생태독성평가

박혜진 ( Hye Jin Park ),김상훈 ( Sang Hoon Kim ),박상우 ( Woo Sang Park ),이재윤 ( Jae Yoon Lee ),이재안 ( Jae An Lee ) 한국물환경학회 2014 한국물환경학회지 Vol.30 No.3

Four clays (both natural and commercial types) mainly used in Korea were tested for removal efficiency of Microcystis spp. and ecotoxicity on Daphnia magna and Vibrio fischeri. Four clays (clay A~D) were composed of 91.9~100% of sand (0.02~0.2 mm in particle size). Clay D consisted of lager particles than other clays. Major elements of the four clays were SiO2 (45.3~62.8%), Al2O3 (18.5~29.7%) and Fe2O3 (5.4~7.9%). They contained kaolinite (clay mineral), quartz, muscovite, and so on. Clay C and D contained montmorillonite, one of the clay minerals improving clay-cell aggregation. For clay A, B and C, removal efficiency of Microcystis spp. was over 60% at 2 g/L. It reached about 100% at over 5 g/L. For clay D, it was over 60% and 95~100% at 5 g/L and 20 g/L respectively. After adding clays, pH decreased. The greatest drop of pH appeared at clay C. Except for addition of 100 g/L clay C, ecotoxicity on D. magna and V. fischeri didn’``t appeared at all dose of clays.

Effects of ultrasound on the synthesis and properties of polyurethane foam/clay nanocomposites

Seo, W. J.,Sung, Y. T.,Kim, S. B.,Lee, Y. B.,Choe, K. H.,Choe, S. H.,Sung, J. Y.,Kim, W. N. Wiley Subscription Services, Inc., A Wiley Company 2006 Journal of applied polymer science Vol.102 No.4

<P>Polyurethane foam (PUF)/clay nanocomposites were synthesized with clay modified by polymeric 4,4′-diphenylmethane diisocyanate (PMDI) with the application of ultrasound. Transmission electron micrographs showed that the interlayer distance increased for the polyurethane (PU)/clay nanocomposites where ultrasound was applied. The results of the transmission electron microscopy and X-ray measurements suggest that the application of ultrasound to the clay modification with PMDI improved the efficiency of the clay modification by the effective breakup of the clay agglomerates and intercalation of the silicate layers. In the mechanical tests of the PUF/clay nanocomposites, the flexural and tensile strengths of the PUF/clay nanocomposites showed the maximum value at 3.0 wt % clay content based on PMDI. These results suggest that the increases in the flexural and tensile strengths were perhaps due to the uniform dispersion of the clay by the application of ultrasound. At the same modified clay content, the fire resistance properties were increased for the PUF/clay nanocomposites with the application of ultrasound compared to the PUF/clay nanocomposites without the application of ultrasound. The cell size and thermal conductivity were decreased for the PUF/clay nanocomposites with the application of ultrasound compared to the PUF/clay nanocomposite without the application of ultrasound. Because of these results, we suggest that the smaller cell size and lower thermal conductivity of the PUF/clay nanocomposites were mainly due to the enhanced dispersion of the clay by the application of ultrasound to the mixture of PMDI and clay. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:3764–3773, 2006</P>

Clay 또는 은 나노 입자를 함유한 불포화 폴리에스테르 수지의 물성에 관한 연구

인교진,목진규,신동현,김주영 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

본 연구에서는 불포화 폴리에스테르 수지에 clay 또는 평균 10 nm의 은 나노 입자를 분산시켜 나노 복합체를 제조하여 그 물성 변화를 관찰하였다. clay를 함유한 나노 복합체에 대하여 XRD 분석을 한 결과, clay 층상 구조에 해당하는 회절 피크가 나타나지 않는 것으로 보아 clay의 층간 거리가 벌어져 있음을 알 수 있었다. 그러나 TEM 관찰 결과를 보면 clay 층이 완전히 박리 된 것은 아니고, clay 층 사이에 고분자 사슬이 삽입되어 있는 삽입형 나노 복합체임을 확인할 수 있었다. 또 불포화 폴리에스테르 은 나노 복합체의 경우 수지 내에 은 나노 입자가 고르게 분산되어 있음을 알 수 있었다. clay를 함유한 나노 복합체의 기계적 물성을 DMA로 분석한 결과 저장 탄성률(E´)은 최대 57% 증가함을 보였다. TGA로 분석한 열적 물성에서는 열분해 온도가 최대 18℃ 정도 증가하였다. 이는 clay가 불포화 폴리에스테르 수지의 기계적, 열적 성질에 영향을 주었기 때문인 것으로 판단되었다. 불포화 폴리에스테르 은 나노 복합체의 경우도 은 나노 입자가 고분자 매트릭스와의 상호작용으로 인해 기계적, 열적 물성이 향상되었다. 또, 은 나노 복합체의 경우 은 특유의 성질인 항균성에 있어서 매우 우수한 물성을 나타내었다. In this study, made nanocomposites that dispersed clay or silver nanoparticles of average 10 nm is unsaturated polyester resins and observed change of the properties. According to the result of XRD analysis about nanocomposites containing clay, diffraction peak that correspond to structure of layerd-clay does not appear and could know that exfoliation of distance between layerd-clay. But, seeing TEM image, layerd-clay is not exfoliated perfectly, and could confirm Intercalated Nanocomposites that polymer chain is intercalated between clay layer. Also, it could know that silver nanoparticles is dispersed in unsaturated polyester resins in the case of unsaturated polyester-silver nanocomposites. The result that analyze mechanical properties of nanocomposites which containing clay by DMA showed Storage Modulus(E´) increased maximum 57 %. Also, Pyrolysis temperature increased maximum 18 ℃ in thermal properties that analyze by TGA. Because clay influenced in mechanical and thermal property of unsaturated polyester resins. In case of UP-silver nanocomposites, advanced mechanical and thermal properties because silver nanoparticles interacted with polymer matrix. Also, it appeared properties in Antibacterial that is silver characteristic property in silver nanocomposites.

Waterborne trifunctionalsilane-terminated polyurethane nanocomposite with silane-modified clay

Subramani, Sankaraiah,Lee, Jun-Young,Choi, Sung-Wook,Kim, Jung Hyun Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of polymer science Part B, Polymer physics Vol.45 No.19

<P>Trifunctional organosilane-modified clay was synthesized and used to prepare waterborne trifunctionalsilane-terminated polyurethane (WSPU)/clay nanocomposite dispersions in this study. Qualitative evidence of the presence of chemically attached silane molecules on clay were confirmed by Fourier transform infrared spectroscopy. The grafted amount and the grafting yield were determined by thermogravimetric analysis and the obtained results were in good agreement with the cation exchange capacity of pristine clay. X-ray diffraction and transmission electron microscopy examinations indicated that the clay platelets are mostly intercalated or partially exfoliated in the SPU matrix with a d-spacing of ∼2.50 nm. Clay does not influence the location and peak broadness of the glass transition temperature of soft segment as well as hard segment domains in the WSPU/clay films. WSPU/clay dispersion with higher clay content exhibits a marginal increase in the average particle size, but silane modified clay has a pronounced effect compared with Cloisite 20A-based nanocomposites. In addition, the incorporation of organophilic clay can also enhance the thermal resistance and tensile properties of WSPUs dramatically through the reinforcing effect. The improvement in water and xylene resistance of the silane modified clay nanocomposites proved that trifunctional organosilane can be used as effective modifiers for clays. Storage stability results confirmed that the prepared nanocomposite dispersions were stable. This method provides an efficient way to incorporate silane modified clay in SPU matrix. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2747–2761, 2007</P>

개질Clay 주입이 응집공정의 유기물 제거에 미치는 영향

유찬서 ( Chan-seo You ),정정조 ( Cheong-jo Cheong ),정상철 ( Sang-chul Jung ),이경동 ( Gyeong-dong Lee ),라덕관 ( Deog-gwan Ra ) 한국환경기술학회 2010 한국환경기술학회지 Vol.11 No.3

정수처리 공정에서 탁도 물질의 주입에 의한 유기물 제거 효율을 향상시키기 위하여 양이온을 점토표면에 치환시켜 개질 한 탁도물질을 제조하고, 이를 응집공정에서 주입하여 유기물 저감효과를 검토하였다. 탁도물질 제거에 적정한 PACS의 적정 주입량은 2mg/L, 탁도 제거율은 92.2%로 나타났다. 응집공정에 탁도물질을 주입하였을 경우 탁도 및 휴믹산제거율은 개질 NH₄-clay> kaolin> acid clay, COD 제거율은 개질 NH₄-clay> acid clay> kaolin의 순으로 높게 나타났다. 상수원수중에 NH₄-clay를 30mg/L첨가할 경우 탁도는 81.8%, 휴믹산은 58.4%, COD는 47.4%가 제거되었다. 응집공정에서 PACS만을 투여하였을 경우에 비하여 NH₄-clay를 첨가함으로서 탁도는 37.7%, 유기물은 32.1%, COD는 44.7%의 제거율이 증진되었다. In order to increase the organic removal efficiency by coagulation with turbidity matters in supply water treatment process, some turbidity matters were made by clay, charged with positive ions on clay surface. And the effect of modified clay on organic matter removal efficiency was investigated in coagulation process. The optimal dosage of PACS to remove the turbidity matters was determined to 2mg/L and turbidity removal efficiency was recorded to 92.2% at the same time. On the case of several modified clay were added to coagulation process respectively, the excellent one to remove turbidity and humic acid were conclusion as NH₄-clay, and kaolin and acid clay were followed. Additionally NH₄-clay was the most effective in COD remove, and acid clay, kaolin were followed. When the addition of 30mg/L NH₄-clay to raw water, the each removal efficiency were recorded as turbidity 81.8%, humic acid 58.4%, COD 47.4%. On the case of addition of NH₄-clay in coagulation process, the turbidity, humic acid, COD removal efficiencies were increased to 37.7 %, 32.1 %, 44.7 %, comparing the PACS single process.

유기탄성체-Clay 나노복합재료 막의 기체투과 특성

남상용,박지순,임지원,정연석,이영무 한국막학회 2006 멤브레인 Vol.16 No.2

일반적으로 탄성체는 특히 고무는 단일성분으로 충분한 물성과 gas barrier성을 나타내지 못하고, 카본블랙과 실리카 등 보강제를 첨가하여 사용되고 있다. 따라서 본 연구에서는 기체 투과성을 낮추기 위해 층상구조를 갖는 점토광물의 일종인 유기실리케이트와 NBR, Ionomer, SEBS (Styrene Ethylene Butadien styrene Copolymer)의 유기탄성체를 이용하여 유기탄성체-clay 나노복합재료 막을 용융법으로 제조하였다. 유기탄성체-clay 나노복합재료 막의 기체 투과 특성은 가압 기체투과장치를 이용하여 실온에서 일정 압력을 유지하며 이산화탄소(CO2), 산소(O2), 질소(N2)가스의 기체투과도를 측정하였다. 유기탄성체-clay 나노복합재료 막은 clay자체의 도입과 층간거리의 확대로 기체분자의 tortuosity를 증가시켜서 기체투과도를 저하시키는 것을 확인하였다. Elastomer-clay nanocomposite membranes were prepared by melt intercalation mothod with internal mixer. We are used NMR, Ionomer, SEBS (Styrene Ethylene Butadien styrene Copolymer) as elastomer, and modified clay. Gas barrier property of the elastomer-clay nanocomposites membranes were investigated by a gas permeability of CO2,;O2,;N2 at room temperature. Gas permeability through the elastomer-clay nanocomposite membranes increased due to increased tortuosity made by intercalation of clay in elastomer.

Growth and Yield Variation of Clay-coated Rice Seeds in Direct Seeding Culture on Dry Paddy

Weon-Young Choi,Hong-Kyu Park,Bon-IL Ku,Young-Jun Mo,Min-Gyu Choi,Sang-Su Kim,Chung-Kon Kim 韓國作物學會 2008 Korean journal of crop science Vol.53 No.3

Clay-coated rice seeds (clay-coated seeds A and B) were directly sown on dry paddy and their growth and yield were compared with the normal drill-sown seeds on dry flat paddy. In clay-coated seeds, germination was 1 day earlier and the emergence rate was higher up to 5% than that of normal drill-sown seeds. But the apparent number of seedling stand per m2 was lower than that of normal drill-sown seeds, which is due to the smaller amount of seeding in clay-coated seeds. At the early growth stage, the plant height of clay-coated seeds A was taller than that of drill-sown seeds, while the plant height of clay-coated seeds B was 0.7 cm shorter than that of drill-sown seeds. At the late growth stage, however, the difference was insignificant in both cases. The maximum tillering stage was 10 days earlier in drill-sown seeds. Lodging index was the lowest in clay-coated seeds B and there was no difference between clay-coated seeds A and drill-sown seeds. The ratio of stem base weight, culm diameter and culm wall thickness were higher in clay-coated seeds, while the lower internodes (4th, 5th and 6th) length was shorter in claycoated seeds than in drill-sown seeds. In clay-coated seeds, the number of panicle per m2 was smaller, while the number of spikelet per panicle was a little larger than in drill-sown seeds. The rate of ripened grain and brown rice 1,000 grain weight were lower in the clay-coated seeds, thus the yield was 98~99% level of drill-sown seeds. Considering that the amount of seeding in clay-coated seeds was two-thirds of that in drill-sown seeds, it is expected that clay coating method could become an additional technique for direct seeding cultivation.

산청토와 백자토 혼합소지의 특성에 관한 연구

공 해 린,여화선 한국도자학회 2019 한국도자학연구 Vol.16 No.1

Clay is the most basic and important material for ceramic art, and the exterior parts such as color, texture and the ease of molding vary from one clay to another. The process of finding diverse and high quality clay in the work is also an important part. In that process, it also makes up for each others disadvantages by mixing different types of clays that are already sold in shop. Sancheong clay has advantages such as good fire resistance, plasticity, heat shock, and external parts such as color and texture, but its high absorption rate makes it difficult to use it for living. In this study experiment was done by mixing White Porcelain clay, which has low absorption, to Sancheong clay to lower its absorption rate. Assuming that White Porcelain clay lowers the absorption rate of Sancheong clay and Sancheong clay lowers the shrinkage rate of White Porcelain clay, and each other's shortcomings would be complemented, results were verified through experiments. The experiment was done by investigating the appearance, absorption rate, drying shrinkage rate and firing shrinkage rate by producing Sancheong clay and White Porcelain clay specimens by 5% unit and fired them in reduction atmosphere at temperature of 1280℃. The colors are listed using a photometric instrument to produce a Munsell color system, and if Sancheong clay was mixed with even five percent, spotted pattern appeared and no other blisters or problems were found in specimens. The absorption rate was 0% when the proportion of White Porcelain clay was 100% and 9.49% when the proportion of Sancheong clay was 100%. The rate of absorption decreased as the more White Porcelain clay was added, and the absorption increased in greater extent from when the proportion of Sancheong clay was 65%. The rate of drying shrinkage was higher with the addition of Sancheong clay, and the rate of drying shrinkage was lower with the addition of Sancheong clay. This shows that adding White Porcelain clay to the Sancheong clay lowers the absorption rate, but increases the firing shrinkage rate. 소지는 도자공예에 있어 가장 기본이고 중요한 재료로 색과 질감 등 외적인 부분과 성형시의 용이함이 각각의 소지마다 다르다. 작업을 함에 있어 보다 더 다양하고 질 좋은 소지를 찾는 과정 또한 중요한 부분이다. 그 과정에서 기존에 판매되고 있는 다른 종류의 소지를 섞어 소지의 단점을 보완하기도 한다. 산청토는 내화성과 가소성, 열 충격 등이 좋고 색감과 질감 등 외적인 부분도 뛰어난 장점이 있으나 흡수율이 높아 생활기로의 활용에 어려운 단점을 가지고 있다. 따라서 본 연구에서는 산청토를 활용하여 생활기를 만들고자 산청토의 흡수율을 낮추기 위해 흡수율이 낮은 백자토를 혼합하여 배합소지 실험을 실시하였다. 백자토는 산청토의 흡수율을 낮추고 산청토는 백자토의 수축률을 낮추어 서로의 단점이 보완될 것임을 가정하고 실험을 통해 결과를 확인해보았다. 실험방법으로는 산청토와 백자토를 5%단위의 비율별로 시편을 제작하고 1280℃에서 환원 소성하여 소지의 외관과 흡수율, 건조수축률과 소성수축률을 각 비율별로 조사하였다. 외관상 나타나는 색상은 측색계를 사용하여 먼셀 값으로 작성하였으며 산청토가 5%라도 섞이면 점박이 무늬가 나타났고 기포나 다른 문제점은 나타나지 않았다. 흡수율은 백자토 비율 100일 때는 0%였고 산청토의 비율이 100일 때는 9.49%로 백자토를 첨가할수록 흡수율이 낮아졌으며 산청토의 비율이 65% 부터 흡수율은 큰 폭으로 증가하였다. 건조수축률은 산청토가 더 첨가될수록 높아졌고 소성수축률은 산청토가 더 첨가될수록 낮아졌다. 이를 통해 산청토에 백자토를 첨가하면 흡수율이 낮아지지만 소성수축률은 커진다는 것을 알 수 있었다.

NBR-Clay 하이브리드 막의 제조 및 물성

남상용,김영진 한국막학회 2004 멤브레인 Vol.14 No.2

본 연구에서는 NBR과 여러 가지의 유기화물로 처리된 MMT type의 clay를 이용하여 NBR-Clay 하이브리드 막을 용융삽입법으로 제조하였다. Internal mixer를 사용하여 clay를 NBR에 분산시켰으며, 제조된 NBR-Clay 하이브리드에서 clay의 특성피크가 다소 감소하거나 이동하는 XRD 결과로부터 clay의 층간거리가 넓어지는 고분자의 clay층간삽입을 확인하였다. Clay의 종류에 따라서 제조된 NBR-Clay 하이브리드 막의 가스투과도, 기계적 물성 및 열적 성질을 측정하였다. NBR-Clay 하이브리드 막은 clay 자체의 도입과 층간거리의 확대로 기체분자의 tortuosity를 증가시켜서 가스투과도를 저하시키는 것을 확인하였다. NBR-Clay hybrid membranes were prepared by melt intercalation method with internal mixer and two roll mills. MMT was intercalated or ekfoliated by the NBR and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was moved and diminished. Gas permeability, mechanical properties and thermal properties of the NBR-Clay hybrid membranes were investigated. Gas permeability through the NBR-Clay hybrid membranes decreased due to increased tortuosity made by intercalation of clay in NBR.