In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, γ-alumina, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using γ-alumina were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the γ-alumina could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for γ-alumina must be implemented, and ozone oxidation and regeneration would be feasible options.

This study examined the color reproducibility and color fastness of digital textile printing for nylon sublimation transfer. After measuring the temperature and time suited to nylon sublimation transfer, the researchers conducted various tests for comparison and analysis including polyester transfer paper on polyester fabric to check dyeing characteristics, color change, sharpness, and the rubbing fastness of the dyeing samples for nylon sublimation transfer. These tests produced the following results. At 185℃ and 187℃, the sublimation transfer dyeing characteristics of nylon were similar to those of polyester and the researchers even observed superior color development in some colors; at a low temperature of 180℃, the sample that was worked on had the lowest level of color development. The examination of color difference (ΔE), which compared L*a*b* values, showed that the ΔE value of magenta was 10.34, that of yellow was 24.70, and that of black was 15.28. These results highlight the important role of heat treatment temperature and time on color development in nylon sublimation transfer. Concerning sharpness, the samples subjected to higher temperature heat treatment exhibited fewer color spreading phenomena around lines. Thus, dyeing properties and fastness can be enhanced by elongating time at low temperatures and shortening time at high temperatures; however, considering production time constraints as well as the need to produce industrially marketable quantities, the findings of this study suggest that the heat treatment temperature most suitable for nylon sublimation transfer is 187℃ for a duration of 50 seconds.

3D프린팅 기술은 산업적 응용을 넘어서 기계 설비 및 각종 장비의 부품생산뿐만 아니라 의료, 식품, 패션에 이르기까지 많은 시제품들의 개발 및 연구가 진행되고 있다. 3D 프린팅 기반 기술의 적용사례를 볼 때 정밀도와 제작 속도 측면에서도 다른 산업에 충분이 활용될 수 있는 기술의 개발이 보고되고 있으나, 아직까지는 시제품 위주로 이용되고 있으며, 향후 3D 프린팅 기술은 4차산업혁명과 관련하여 광범위한 분야에서 응용될 수 있는 완성품이나 부품제작에 이용될 것으로 예상된다. 본 연구에서는 탄소나노 재료중 대표적으로 많이 이용되는 환원그래핀 [rGO(reduced graphene oxide)]과 전도성 고분자중 생체 친화적인 특성을 갖는 폴리피롤[Ppy(Polypyrrole)]의 복합체를 생분해성 고분자인 폴리카프로락톤 [PCL(polycaprolactone)]과 혼합하여 3D 프린팅용 전도성 레진을 개발하고자 하였다. 결과로, 폴리피롤과 환원그래핀 각각 5 wt%, 0.75 wt% 에서 최적의 전기적 특성을 나타내었으며, 환원그래핀의 농도에 따른 표면분석에서도 이와 부합하는 결과를 확인 할 수 있었다. 본 연구를 통하여 제조된 전도성 레진은 3D 프린팅 뿐만 아니라, 다른 산업분야의 전자재료에도 적용이 가능할 것으로 사료된다.

목적 : 본 연구에서는 체계적 고찰을 통해 3D 프린팅 기술을 상지보조기 제작에 적용한 사례에 대해 알아 보고, 향후 작업치료사가 임상현장에서 상지보조기 제작에 3D 프린팅 기술을 적용할 때 필요한 정보를 정리하여 임상적용에 유용한 기초자료를 제시하고자 한다. 연구방법 : 2013년부터 2017년까지의 최근 5년간의 논문을 전자 데이터베이스 RISS, KISS, Scopus, PubMed와 Google Scholar를 사용하여 검색하였다. 검색 키워드로는 “3D Printing AND Orthosis OR Splint OR Brace”을 사용하였다. 검색된 논문은 2차 분류를 거쳐 최종적으로 16개의 논문을 선정하였으며 이를 분석하고 고찰하였다. 결과 : 분석대상 논문의 약 80%가 단일대상 실험연구 및 사례연구로 질적수준은 낮은 편이었다. 제작자의 전공을 분석한 결과, 크게 4가지 계열로 구분됐으며, 그 중에서 공학계열이 가장 많았다. 다음으로는 보건계열이 많았으며, 작업치료전공자는 2명이었다. 제작된 상지보조기의 종류는 6가지였으며, 그 중에서 코크 업 보조기와 손가락 보조기가 가장 많이 제작되었다. 제작에 가장 많이 사용된 소재는 플라스틱 소재중 하나인 ABS수지였다. 분석된 논문에서 사용된 제조공법은 총 4가지가 있었으며, 가장 많이 사용된 제조공법은 FDM방식이다. 상지보조기 제작을 위한 상지 측정방법으로는 3D 스캐너가 가장 많이 사용되었다. 결론 : 이번 연구를 통하여 3D 프린팅 기술을 적용한 상지보조기 제작방법에 대해 알 수 있었다. 이를 근거로 작업치료사의 업무범위 중 한가지인 상지보조기 제작에 3D 프린팅 기술을 적용할 수 있는 기초근거를 제공하고, 추후 연구에 대한 방향성을 제시하고자 하였다. 본 연구 결과를 바탕으로 작업치료분야에서 3D 프린팅 기술을 적용한 상지보조기 개발 및 연구가 더욱 활발하게 이루어질 것으로 기대한다.

In this study, ZrO2 ceramic ink was formulated for additive manufacturing three dimensional structure using dispenser printing technique. Ceramic ink with various ZrO2 loading (30, 40, 50vol%) was prepared to evaluate their rheological properties and printability. High ZrO2 loading ZrO2 ceramic ink showed higher elastic modulus and improved shape retention, when the ceramic ink was printed and sintered at 1450 oC for 1h. Microstructural analysis of printed ZrO2 objective indicated that high ZrO2 loading objective showed lower porosity and smaller pore size.

This paper aims at finding some lessons applicable to successful implementation of ‘The 3D Printing R/D Project’ through both examining the process of adopting overseas industrialized housing production technological knowhow by home builders during the 1970's~1980's period and thereafter until now the various efforts to adjust the technologies efficiently to the Korea‘s unique situation. Some meaningful lessons can be summarized as follows; Ⅰ) Deep understanding of 3DP technological know-why along with its inheritance, Ⅱ) Readjusting of R/D period and goals(cf. Global leader Winsun's 15 years experiment), Ⅲ) Restructuring for more collaborative R/D B&E system among participating researchers Ⅳ) Fostering 3DP expert-engineers and technicians from the early stage, Ⅴ) Clearing legal barriers in users' adopting 3DP methods necessary, Ⅵ) Development of appropriate building material besides concrete. Therefore, it is highly recommended that the above-mentioned 6 lessons positively accepted and applied to the Research Implementation Plan in due course, especially by KICT consortium and KAIA under the guidance of Ministry of Land, Infrastructure and Transport.

Ceramic ink-jet printing has become a widespread technology in ceramic tile and ceramicware industries, due to its capability of manufacturing products on demand with various designs. Generally, thermally stable ceramic inks of digital primary colors(cyan, magenta, yellow, black) are required for ink-jet printing of full color image on ceramic tile. Here, we synthesized an aqueous glass-ceramic ink, which is free of Volatile organic compound(VOC) evolution, and investigated its inkjet printability. CoAl2O4 inorganic pigment and glass frit were dispersed in aqueous solution, and rheological behavior was optimized. The formulated glass-ceramic ink was suitably jetted as single sphere-shaped droplets without satellite drops. After ink-jet printing and firing processes, the printed glass-ceramic ink pattern on glazed ceramic tile was stably maintained without ink spreading phenomena and showed an improved scratch resistance.

Scaffolds of cell substrates are biophysical platforms for cell attachment, proliferation, and differentiation. They ultimately play a leading-edge role in the regeneration of tissues. Recent studies have shown the potential of bioactive scaffolds (i.e., osteo-inductive) through 3D printing. In this study, rice bran-derived biocomposite was fabricated for fused deposition modeling (FDM)-based 3D printing as a potential bone-graft analogue. Rice bran by-product was blended with poly caprolactone (PCL), a synthetic commercial biodegradable polymer. An extruder with extrusion process molding was adopted to manufacture the newly blended “green material.” Processing conditions affected the performance of these blends. Bio-filament composite was characterized using field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDX). Mechanical characterization of bio-filament composite was carried out to determine stress-strain and compressive strength. Biological behaviors of bio-filament composites were also investigated by assessing cell cytotoxicity and water contact angle. EDX results of bio-filament composites indicated the presence of organic compounds. These bio-filament composites were found to have higher tensile strength than conventional PCL filament. They exhibited positive response in cytotoxicity. Biological analysis revealed better compatibility of r-PCL with rice bran. Such rice bran blended bio-filament composite was found to have higher elongation and strength compared to control PCL.

In this study, H13 tool steel sculptures are built by a metal 3D printing process at various laser scan speeds. The properties of commercial H13 tool steel powders are confirmed for the metal 3D printing process used: powder bed fusion (PBF), which is a selective laser melting (SLM) process. Commercial H13 powder has an excellent flowability of 16.68 s/50 g with a Hausner ratio of 1.25 and a density of 7.68 g/cm3. The sculptures are built with dimensions of 10 × 10 × 10 mm3 in size using commercial H13 tool steel powder. The density measured by the Archimedes method is 7.64 g/cm3, similar to the powder density of 7.68 g/cm3. The hardness is measured by Rockwell hardness equipment 5 times to obtain a mean value of 54.28 HRC. The optimum process conditions in order to build the sculptures are a laser power of 90 W, a layer thickness of 25 μm, an overlap of 30%, and a laser scan speed of 200 mm/s.

This study aimed to create 3D-printed insoles for flat-footed senior men using 3D systems. 3D systems are product-manufacturing systems that use 3-dimensional technologies like 3D scanning, 3D modeling, and 3D printing. This study used a 3D scanner (NexScan2), 3D CAD programs including Rapidform, AutoCAD, SolidWorks, Nauta+ compiling program, and a 3D printer. In order to create insoles for flat-footed senior men, we analyzed horizontal sections of 3D foot scans We selected 20 flatfooted and 20 normal-footed subjects. To make the 3D insole models, we sliced nine lines on the surface of the subjects’ 3D foot scans, and plotted 144 points on the lines. We calculated the average of these 3D coordinates, then located this average within the 3D space of the AutoCAD program and created 3D sole models using the loft surface tools of the SolidWorks program. The sole models for flat feet differed from those of normal feet in the depth of the arch at the inner sideline and the big toe line. We placed the normal-footed sole model on a flat-footed sole model, and the combination of the two models resulted in the 3D insole for flat feet. We printed the 3D modeled insole using a 3D printer. The 3D printing material was an acrylic resin similar to rubber. This made the insole model flexible and wearable. This study utilized 3D systems to create 3D insoles for flat-footed seniors and this process can be applied to manufacture other items in the fashion industry as well.

인쇄에서 종이의 인쇄적성은 인쇄품질을 결정하는 중요한 요소이며, 이를 보완하기 위해 많은 연 구들이 진행되어 왔다. 특히, 잉크젯에 의한 종이의 인쇄적성은 앞으로 전자융합산업의 발달을 고려해본 다면 더욱 주요한 연구가 될것이다. 따라서, 본 연구는 잉크젯 시스템에서 사용하는 CMYK 프로세스 잉 크의 인쇄적성을 파악하고 종이의 특성에 따라 색재현 정도를 ICC 프로파일값을 활용하여 분석하고자 하 였다. 잉크젯의 토출 특성을 이해하기 노즐에서의 잉크 유동을 시뮬레이션 하였고 종이의 재질이 다른 두 종(갱지 및 인화지)의 피인쇄체 위에 각기 다른 망점으로 인쇄하여 색재현 평가를 실시하였다. 각 종이의 관련 특징들 즉, 거칠음도, 투기도, 광택도 및 압축도,과 이에따른 색재현 특성을 ICC 프로파일모니터링에 쓰이는 ΔE값으로 표현하였다. 그 결과 상대적으로 종이의 낮은 거칠음도와 투기도 그리고 높은 압축력을 가지는 인화지에서 더 높은 색재현이 이루어짐을 알 수 있었다.

3D프린팅 공법은 설계 데이터 및 제품의 특성에 따라 액체 또는 분말가루 형태의 폴리머, 금속 등의 재료를 사용한다. 3D프린팅 공법의 제조방식은 적층방식으로 입체구조물을 층층이 쌓아올려 3차원형상을 제조하는 방식을 말한다. 3D프린팅 기술은 30년(1980년대) 전에 개발된 기술이지만 최근 몇 년 사이에 업계의 관심이 집중되고 있다. 3D프린팅 기술의 적용범위는 기계 산업분야에서 의료분야, 항공 분야, 건설 및 토목분야 등으로 그 범위가 점점 확대되어가 고 있다 컨투어크래프팅(Contour Crafting)은 미국 남가주대학에서 15년(2000) 전에 세라믹재료를 이용하여 개발된 3D프린팅 공법이다. Trowel 구조를 도입하여 3D프린팅 공법의 핵심적 단점인 외부표면을 매끄럽게 하면서 3D자유형상을 제작하는 것이다. 현재의 이 공법은 시멘트를 이용 하여 구조물의 부가구성물뿐만이 아니라 전체구조물을 자동으로 만드는 것을 목적으로 한다. 또한 각층의 두께 및 폭이 일반 3D프린팅 공법과 비교할 수 없이 크고 넓게 함으로 건설 및 토목분야의 적용이 가능하다. 특히, 콘크리트재료를 이용하여 토목용 2차구조물 제작에 대한 기초적인 조사 및 개념을 상세히 설명된다

Numerous studies have been performed on the nutritional properties and health benefits of rice bran. However no previous reports have investigated rice bran-derived products as a biomaterial for bone formation. Thus, the aim of this study was fabricate composite filaments by combining the agricultural by-product rice bran and polycaprolactone (PCL), which has high biodegradability. It is suggest a possibility as a high value-added biomaterial capable of utilizing 3D printing. First, In order to investigate the optimal ratio of rice bran and PCL, the mixing ratios were set to 0%, 10%, 20%, 50% respectively, and the mixed filaments were defined as r-PCL filaments. The r-PCL filament was analyzed by FE-SEM and EDX for morphological characteristics and mechanical characteristics were analyzed by stress-strain, water contact angle, cytotoxicity test. Our findings confirm the possibility of manufacture environmentally friendly composite bio-filaments for FDM (Fused Deposition Modeling) based 3D printing technology. Thus, we could establish biomimetic scaffolds based on bio-printer filaments mixed with agricultural by-product.

삼차원(3D) 프린터의 개발과 보급에 따라 현대의 소비자들은 자신이 원하는 제품을 집에서 3D프린팅 할 수 있는 시대에 살고 있다. 3D프린팅을 통해 소비자 맞춤형 제작이 활성화되기 위해서는 3D프린터와 호환되는 디지털 설계도 를 소비자 스스로 제작할 수 있어야 한다. 또한 최적의 프린팅 재질과 온도를 설정할 수 있어야 하고 3D프린터의 유지보수에 비용을 감당해야 한다. 더하여 혹시 있을지 모르는 디자인에 대한 지식재산권 문제에 대응할 수 있어야 한다. 그러나 실상 소비자가 이러한 문제들에 대응하기는 어렵기 때문에 소비자가 원하는 방향으로 3D프린팅을 대행해 줄 수 있는 서비스가 개발될 필요가 있다. 이런 동기에서 출발한 본 연구는 소비자가 원하는 3D프린팅 서비스 방식이 무엇인지에 통찰을 얻기 위해 세계적인 온라인 3D프린팅 제품판매 업체인 Shapeways (www.shapeways.com)에 대한 사용자 경험을 다양한 측면에서 탐색하였다. 그 결과 Shapeways의 사용성, 검색과정, 가격 적절성, 재방문의도, 디자인 의 다양성, 디자인 만족도에 대한 양적 평가에서 전반적으로 낮은 평가를 받았다. 또한 다양한 언어지원, 제품 제작과정 공개 및 온-오프라인 사이트 동시운영, 디자이너 중심의 소비자 맞춤형 제작 서비스, 배송 안전성과 제품 내구성에 대한 확신을 줄 수 있는 서비스, 표면의 마감처리 서비스가 필요하다는 건설적인 의견을 통해 소비자 맞춤형 3D프린팅 서비스에 대한 통찰을 획득하였다. 본 연구가 3D프린팅 서비스 플랫폼 개발뿐 아니라, 관련된 산업 및 연구에도 폭넓은 시사점을 줄 것으로 기대한다.

Ink-jet printing techniques with ceramic ink, which contains ceramic pigments as colorant, are in increasingly use in the ceramic industry. Generally, ceramic pigments that are produced by conventional method show diameters of several micrometers; these micrometer sized particles in the ink-jet printing process can cause undesirable behavior such as print head nozzle clogging. To prevent this problem, a particle size reduction process is required. In this study, CMYK (cyan, magenta, yellow, black) pigments were synthesized via solid state method. Each pigment particle was milled to submicron size by an attrition mill. The effects of micronizing on the morphology, mechanical property, crystal structure and color property of the CMYK ceramic pigments were investigated by field emission scanning electron microscopy (FE-SEM), particle size analysis (PSA), X-ray diffraction (XRD) and CIE L*a*b*.

Foods are becoming more customized and consumers demand food that provides great taste and appearance and that improves health. Food three-dimensional (3D)-printing technology has a great potential to manufacture food products with customized shape, texture, color, flavor, and even nutrition. Food materials for 3D-printing do not rely on the concentration of the manufacturing processes of a product in a single step, but it is associated with the design of food with textures and potentially enhanced nutritional value. The potential uses of food 3D-printing can be forecasted through the three following levels of industry: consumer-produced foods, small-scale food production, and industrial scale food production. Consumer-produced foods would be made in the kitchen, a traditional setting using a nontraditional tool. Small-scale food production would include shops, restaurants, bakeries, and other institutions which produce food for tens to thousands of individuals. Industrial scale production would be for the mass consumer market of hundreds of thousands of consumers. For this reason, food 3D-printing could make an impact on food for personalized nutrition, on-demand food fabrication, food processing technologies, and process design in food industry in the future. This article review on food materials for 3D-printing, rheology control of food, 3D-printing system for food fabrication, 3D-printing based on molecular cuisine, 3D-printing mobile platform for customized food, and future trends in the food market.

Graphene has shown exceptional properties for high performance devices due to its high carrier mobility. Of particular interest is the potential use of graphene nanoribbons as field-effect transistors. Herein, we introduce a facile approach to the fabrication of graphene nanoribbon (GNR) arrays with ~200 nm width using nanoimprint lithography (NIL), which is a simple and robust method for patterning with high fidelity over a large area. To realize a 2D material-based device, we integrated the graphene nanoribbon arrays in field effect transistors (GNR-FETs) using conventional lithography and metallization on highly-doped Si/SiO2 substrate. Consequently, we observed an enhancement of the performance of the GNRtransistors compared to that of the micro-ribbon graphene transistors. Besides this, using a transfer printing process on a flexible polymeric substrate, we demonstrated graphene-silicon junction structures that use CVD grown graphene as flexible electrodes for Si based transistors.

3D 프린틴 공법은 설계 데이터 및 제품의 특성에 따라 액체 또는 분말가루 형태의 폴리머, 금속 등의 재료를 가공하여 적층방식으로 층층이 쌓아올려 3차원으로 입체구조물을 제조하는 방식을 말한다. 3D 프린팅 기술은 1980년대에 개발된 기술이지만 최근 몇 년 사이에 업계의 관심이 집중되고 있다. 3D 프린팅 기술의 적용범위는 기계산업분야에서 의료분야, 항공 분야, 건설 및 토목분야 등으로 그 범위가 점점 확대되어가고 있다 컨투어크래프팅(Contour Crafting)은 미국 남가주대학에서 개발되고 있는 3D 프린팅공법으로 시멘트를 이용하여 구조물의 부가구성물뿐만이 아니라 전체구조물을 자동화로 만드는 것을 목적으로 한다. 3D 프린팅공법의 핵심적인 단점인 외부표면의 정도를 매끄럽게 하기 위하여 Trowel 메커니즘을 도입하여 3D 자유형상을 만드는 것이다. 또한 건설 및 토목분야의 적용을 목적으로 함으로 각층의 두께 및 폭이 일반 3D프린팅공법과 비교할 수 없이 크고 넓다. 이 논문은 선회하는 Side towel을 사용하여 3D 자유곡면의 제작에 대한 기초적인 조사 및 개념을 보여준다. 특히, 세라믹재료를 이용하여 실험과 개발과정 및 장래의 적용범위가 상세히 설명 된다.