• 한국산업보건학회지
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• 제28권3호
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• pp.241-256
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• 2018

Objectives: This study aimed to review the characteristics of three-dimensional printing technology focusing on printing types, materials, and health hazards. We discussed the methodologies for exposure assessment on hazardous substances emitted from 3D printing through article reviews. Methods: Previous researches on 3D printing technology and exposure assessment were collected through a literature review of public reports and research articles reported up to July 2018. We mainly focused on introducing the technologies, printing materials, hazardous emissions during 3D printing, and the methodologies for evaluation. Results: 3D printing technologies can be categorized by laminating type. Fused deposition modeling(FDM) is the most widely used, and most studies have conducted exposure assessment using this type. The printing materials involved were diverse, including plastic polymer, metal, resin, and more. In the FDM types, the most commonly used material was polymers, such as acrylonitrile-butadiene-styrene(ABS) and polylactic acids(PLA). These materials are operated under high-temperature conditions, so high levels of ultrafine particles(mainly nanoparticle size) and chemical compounds such as organic compounds, aldehydes, and toxic gases were identified as being emitted during 3D printing. Conclusions: Personal desktop 3D printers are widely used and expected to be constantly distributed in the future. In particular, hazardous emissions, including nano sized particles and various thermal byproducts, can be released under operation at high temperatures, so it is important to identify the health effects by emissions from 3D printing. Furthermore, appropriate control strategies should be also considered for 3D printing technology.

• 한국정밀공학회지
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• 제31권12호
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• pp.1085-1091
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• 2014

Recently, 3D printing has received increasing attention due to its boundless potentials. Because 3D printing starts from 3D geometry information, computer-aided design (CAD) is an essential technology to build 3D geometry data. These days, education of 3D CAD for engineering students has been changed from the theoretical lecture to practical design training using commercial CAD software. As a result, open-ended design projects have replaced the traditional theoretical examinations to evaluate students' outcomes. However, such design projects are not enough to evaluate students' outcomes because their results are expressed in two-dimensional ways. In this paper, applications of 3D printing in engineering design education are discussed by describing the procedure and outcomes of design projects. It was found that the use of 3D printing could improve students' outcomes by fabricating real physical models out of their designs.

• 한국산학기술학회논문지
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• 제15권10호
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• pp.6336-6343
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• 2014

본 연구는 최근 사회적으로 대두되고 있는 3D 프린팅 기술에 대하여 고찰하고, 건축적인 활용 방안을 모색함에 있어 활용 방안과 경제적인 관점에서 비교 및 분석하는 것이 목적이다. 이는 근접한 미래에 3D 프린팅 기술에 의해 생산, 유통 등의 전반적인 패러다임의 변화가 예상되고, 건축분야 역시 그 변화의 흐름을 맞을 것이다. 이에 3D 프린팅 기술의 건축에서 활용 방안을 모색함은 앞으로 3D 프린팅 기술로 인하여 바뀌는 건축환경에 대하여 대비하기 위함이다. 본 연구를 위하여 3D 프린팅 기술의 현황과 건축에서 사용되는 3D 프린팅 기술에 대하여 조사하고, 3D 프린팅 기술의 건축적 활용 방식과 현재 시공 방식을 경제적인 부분에서 비교 분석 하였다. 현재 건축분야에서의 3D 프린팅 활용기술은 아직 실용화 단계이나, 현재의 시공 방식과 경제성으로 비교해 보면, 전체 비용을 낮출 수 있으며, 향후 기술의 발전과 더불어 이러한 비용은 더욱 감소될 것으로 보인다. 이에 따라서 앞으로 3D 프린팅 기술의 건축적 활용 방안에 대한 지속적인 기술 개발 및 관심이 필요하다.

• 대한치과의사협회지
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• 제58권7호
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• pp.448-459
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• 2020

In addition to extensive research on polymer and metal three-dimensional (3D) printing, ceramic 3D printing has recently been highlighted in various fields. The biggest advantage of 3D printing has the ability to easily create any complex shape. This review introduces the 3D printing technology of ceramics according to the type of material and deals with the latest related research in the industrial field including the biomedical engineering field. Finally, the future of ceramic 3D printing technology available in dentistry will be discussed.

• 한국구조물진단유지관리공학회 논문집
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• 제23권4호
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• pp.131-136
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• 2019

굳지 않은 콘크리트의 적층성은 콘크리트 3D 프린팅의 핵심 요소로써 필라멘트의 변형 및 붕괴 없이 일정한 높이로 적층하는 성능이다. 적층성은 항복응력과 밀접한 관련이 있으며, 항복응력이 높을수록 우수하다. 또한, 굳지 않은 콘크리트는 압출된 후 시간경과에 따라 경화되면서 전단응력이 증가하기 때문에 적층성이 높아지게 된다. 따라서, 콘크리트 3D 프린팅 시 굳지 않은 콘크리트의 적층성 확보를 위해서는 출력되는 레이어 사이의 적절한 시간 간격(Printing Time Gap, 이하 PTG)이 필요하다. PTG가 증가함에 따라 적층성은 증가하지만, PTG가 과다하게 커지면 출력된 레이어 간의 부착성능이 감소하며, 출력시간이 길어짐에 따라서 압출성능이 저하될 수 있다. 이 연구에서는 100 MPa급 고강도 콘크리트 배합에 적합한 적층성을 확보하기 위하여 PTG를 변수로 한 3D 프린팅 실험을 수행하였으며, 이와 더불어 콘크리트 3D 프린팅 방법을 유사하게 모사할 수 있는 모의 적층실험 방법의 유효성을 검토하기 위하여 모의 적층실험을 수행하였다.

• 산업식품공학
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• 제21권1호
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• pp.12-21
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• 2017

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.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1619-1625
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• 2016

Recently, as the public interests about the 3D printing technology are increased, various kinds of 3D printers are being released. But, they are limited to use because they cannot fabricate an object which is larger than the printer's printing volume. To relieve this problem, we propose an interactive 3D mesh editing system for 3D printing the object that is larger than the printing volume. The proposed 3D editing system divides the input 3D mesh using the user's line drawings defining cutting planes and it attaches various connectors. The output meshes are guaranteed to fabricate without post-processing. The printed parts can be assembled using the connectors. Our proposed system has an advantage that it can be used easily by non-professional 3D printer users.

• 한국기계가공학회지
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• 제14권3호
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• pp.1-8
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• 2015

Recently, a great interest in 3D printing has emerged, although many existing 3D printing technologies were first developed 2-3 decades ago. There are many mature 3D printing processes and materials; however, active research and development efforts are ongoing in this area to advance the technologies. Several companies have already started to use 3D printed parts as actual components. Many low-cost 3D printers have been released on the market, which are of particular interest to educators and hobbyists. This paper provides a brief review of 3D printing technologies and research trends. In addition, several state-of-the-art technologies and applications are introduced.

• 한국분말재료학회지
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• 제30권4호
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• pp.318-323
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• 2023

The thermoelectric effect, which converts waste heat into electricity, holds promise as a renewable energy technology. Recently, bismuth telluride (Bi2Te3)-based alloys are being recognized as important materials for practical applications in the temperature range from room temperature to 500 K. However, conventional sintering processes impose limitations on shape-changeable and tailorable Bi₂Te₃ materials. To overcome these issues, three-dimensional (3D) printing (additive manufacturing) is being adopted. Although some research results have been reported, relatively few studies on 3D printed thermoelectric materials are being carried out. In this study, we utilize extrusion 3D printing to manufacture n-type Bi_1.7Sb_0.3Te₃ (N-BST). The ink is produced without using organic binders, which could negatively influence its thermoelectric properties. Furthermore, we introduce graphene oxide (GO) at the crystal interface to enhance the electrical properties. The formed N-BST composites exhibit significantly improved electrical conductivity and a higher Seebeck coefficient as the GO content increases. Therefore, we propose that the combination of the extrusion 3D printing process (Direct Ink Writing, DIW) and the incorporation of GO into N-BST offers a convenient and effective approach for achieving higher thermoelectric efficiency.

• 한국의류학회지
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• 제45권6호
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• pp.1052-1062
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• 2021

This study aims to confirm the possibility of Ultra-Violet (UV)-printed 3D printing materials using thermal polyurethane (TPU) with CMYK colors by applying an eco-friendly UV digital printing process. A UV-printed 3D printing TPU material was prepared with cycles of UV printing and CMYK colors. Dyeability of the 3D TPU samples with cycles of UV printing and CMYK were analyzed for thickness, weight, surface roughness, reflectance, colorimetry, and K/S values. The thickness and weight of 3D-printed TPU samples with cycles of UV printing are increased with overprints from 1 to 5. The surface roughness of 3D-printed TPU samples with increasing UV prints were decreased, meaning that the surface of TPU samples becomes gradually smoother. The reflectance spectra of CMYK UV-printed TPU samples showed the surface reflectance within each characteristic wavelength of CMYK. The 3D-printed TPU samples, subjected to UV printing twice or more, showed low surface reflectance. After examining the L^*a^*b^* of the 3D-printed TPU samples by the cycles of UV printing, the study found that the more UV got printed more than 2 times, the closer the color to each CMYK.