• 한국기계가공학회지
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• 제18권7호
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• pp.83-89
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• 2019

In the conventional casting and forging method, there is a disadvantage that a mold is an essential addition, and a production cost is increased when a small quantity is produced. In order to overcome this disadvantage, a metal 3D printing production method capable of directly forming a shape without a mold frame is mainly used. In particular, overseas research has been conducted on various materials, one of which is a metal printer. Similarly, domestic companies are also concentrating on the metal printer market. However, In this case of the conventional metal 3D printing method, it is difficult to meet the needs of the industry because of the high cost of materials, equipment and maintenance for product strength and production. To compensate for these weaknesses, printers have been developed that can be manufactured using sand mold, but they are not accessible to the printer company and are expensive to machine. Therefore, it is necessary to supply three-dimensional casting printers capable of metal molding by producing molds instead of conventional metal 3D printing methods. In this study, we intend to reduce the unit price by replacing the printing method used in the sand casting printer with the FDM method. In addition, Ag paste is used to design the output conditions and enable ceramic printing.

• 한국기계가공학회지
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• 제20권2호
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• pp.38-44
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• 2021

To cater to the transition from single-color to multicolor/multi-material printing, this paper proposes a cartridge-replacing type multi-nozzle Fused Depositon Modeling(FDM) three-dimensional (3D) printer. In the test printing run, tool change failure/wobble/layer shift occurred. It was confirmed that improper support was the cause of this tool change failure. As a solution, spline and electromagnetic cartridges were designed. Wobble was caused by machine vibration and the motor stepping out. To minimize wobble, an additional Z-axis was installed, and the four-point bed leveling method was used instead of the three-point bed leveling method. The occurrence of layer shift was ascribed to the eccentricity of the Z-axis lead screw. Therefore, slit coupler was replaced with an Oldham type. In addition to the mechanical supplementation, the control environment was integrated to prevent accidents and signal errors due to wire connections. Before the final test printing run, a rectifier circuit was added to the motor to secure precise control stability. The final test printing run confirmed that the wobble/layer shift phenomenon was minimized, and the maximum error between layers was reduced to 0.05.

• 한국기계가공학회지
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• 제14권4호
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• pp.62-72
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• 2015

Interest in three-dimensional (3D) printing processes has grown significantly, and several types have been developed. These 3D printing processes are classified as Selective Laser Sintering (SLS), Stereo-Lithography Apparatus (SLA), and Fused Deposition Modeling (FDM). SLS can be applied to many materials, but because it uses a laser-based material removal process, it is expensive. SLA enables fast and precise manufacturing, but available materials are limited. FDM printing's benefits are its reasonable price and easy accessibility. However, metal printing using FDM can involve technical problems, such as suitable component supply or the thermal expansion of the heating part. Thus, FDM printing primarily uses materials with low melting points, such as acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) resin. In this study, an FDM process for enabling metal printing is suggested. Particularly, the nozzle and heatsink for this process are focused for stable printing. To design the nozzle and heatsink, multi-physical phenomena, including thermal expansion and heat transfer, had to be considered. Therefore, COMSOL Multiphysics, an FEM analysis program, was used to analyze the maximum temperature, thermal expansion, and principal stress. Finally, its performance was confirmed through an experiment.

• 한국방사선학회논문지
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• 제12권7호
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• pp.909-917
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• 2018

3D 프린팅 기술은 4차산업 혁명 중 제조업의 혁신적인 기술로서 전망되고 있으며, 현재 바이오 의료 분야를 포함한 다양한 분야에서 활용되고 있다. 본 연구에서는 이러한 3D 프린팅 기술을 이용한 제작 원료에 대한 방사선 차폐능을 평가하고자 몬테카를로 전산모사를 통해 프린팅 원료에 대한 검증을 수행하였다. 현재 범용으로 사용되는 FDM 방식의 3D 프린터에서 이용 가능한 원료들을 대상으로 하였으며, ICRU phan tom과 차폐체를 모의 모사한 후 방사선의 종류 및 에너지에 따른 입자 플루언스 평가를 통해 차폐 효과에 대해 분석하였다. 그 결과, 광자선의 경우 에너지 증가에 따라 차폐 효과는 점차 감소되는 경향을 보였고, 원료별 차폐 효과는 TPU, PLA, PVA, Nylon, ABS 순서로 점차적으로 낮아지는 결과를 나타냈다. 중성자선의 경우, 5~10 mm의 낮은 두께에서 반대로 선속이 증가되는 현상을 보였으나, 일정 두께 이상에서는 유효한 차폐 효과를 나타내었으며, 프린팅 원료별 차폐 효과는 Nylon, PVA, ABS, PLA, TPU 순서로 점차 낮아지는 결과를 보였다.

• 한국기계가공학회지
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• 제18권11호
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• pp.96-102
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• 2019

Reverse engineering involves duplicating a physical part by measuring and analyzing its physical dimensions, features, and material properties. By combining reverse engineering with three-dimensional (3D) printing, engineers can simply fabricate and evaluate functional prototypes. This design methodology has been attracting increasing interest with the advent of the Fourth Industrial Revolution. In the present study, we apply reverse engineering and 3D printing technologies to evaluate a fabricated automotive inner ring prototype. Through 3D printing, inner rings of various densities were prepared. Their physical dimensions were measured with a 3D scanning system. Of our interest was the effect of inner ring density on the physical dimensions of the fabricated prototype. We compared the design dimensions and physical dimensions of the fabricated prototypes. The results revealed that even the 20% density of inner ring was effective for 3D printing in terms of satisfying the design requirements.

• 패션비즈니스
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• 제24권4호
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• pp.130-143
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• 2020

The development of three-dimensional (3D) printing technology is bringing new innovations to various fields such as health care, architecture, and fashion. 3D printing can be manufactured to suit the size of the consumer's body, modify the design to meet their tastes, and produce small quantities of various products. Therefore, 3D printing in the field of fashion has great potential. The purpose of this study was to investigate various application models of 3D printing for fashion design and analyze their characteristics after developing the fashion garment samples. First, the background of 3D printing was reviewed then, fashion designed by a 3D printing application was analyzed. As a result, four types of 3D printing applications were developed: object-attached, linkage, kinematics, and assembly. The object-attached type was the method of printing 3D material as an object in the intended shape and form and was attached to the garment by sewing. The linkage type referred to printing 3D material in small pieces of certain shapes that could be linked. The kinematics type was structures with hinges that could flex to fit the human body. The assembly type referred to developing 3D materials in female and male pieces such as nuts and bolts. By providing the advantages, disadvantages, trial-and-errors, and challenges of the 3D printing fashion design process, this study contributes to the effective applications and possibilities of future design.

• 한국콘텐츠학회논문지
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• 제14권11호
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• pp.370-377
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• 2014

최근 3D 프린팅 기술은 다양한 의학 분야에서 활용하고 있으며, 기존의 절삭가공 보다 제작시간과 비용, 과정측면에서 매우 효율적이다. 특히 정형외과에서는 수술시간, 수술 정확성 등의 개선과 환자의 고통 감소와 재수술을 최소화하는 방법으로 관심이 집중되고 있다. 그러나 기존 연구에 사용된 3D 프린터는 하드웨어 및 소프트웨어의 기술적 활용성, 재정적 가용성 등의 문제로 현재 병원에서 일반적으로 널리 사용되지 못하고 있는 실정이다. 본 연구에서는 이를 해결하기 위해 CT 영상을 Open Source DICOM Viewer와 STL 파일변환 프로그램, FDM 와이어 적층가공방식의 조립형 3D 프린터로 골반 골절 모델을 직접 제작하여 비용과 시간을 단축하고 사전 수술계획에 활용하였다. 6명의 불안정성 골반골절 수술환자의 맞춤형 골 모델을 제작한 후 대학병원 정형외과 임상의에게 골절수술 전에 제공하여 임상적 활용 가능 여부에 대한 검토와 분석의견 결과 정밀도, 해상도가 수술계획에 사용하여도 유용한 것으로 판단되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.154-155
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• 2021

Appearance finish is important for amorphous buildings to maximize amorphousness, and GFRC, glass, and metal are mostly used as exterior materials for amorphous buildings currently applied. However, the existing exterior materials showed limitations in amorphous expression, texture, and color expression. In this study, a 3D stereoscopic panel mold was manufactured using the FDM method, one of the 3D printing technologies, and 3D stereoscopic panel production was reviewed using Ultra High Performance Concrete (UHPC), which has excellent physical and mechanical performance and expression. In order to overcome the limitations of unstructured expression, a UHPC 3D stereoscopic panel using the FDM method, one of the 3D printing technologies, was manufactured. Unlike steel molds, FRP molds, and EPS molds, the FDM method can be applied to various materials, and complex shapes are implemented. If it is used using recyclable materials as well as PLA filaments used in the FDM method, it will overcome the limitations of amorphous expression and activate the production of 3D stereoscopic panels that have secured eco-friendliness.

• 한국의상디자인학회지
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• 제17권2호
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• pp.125-143
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• 2015

This study has investigated the status of utilizing 3D printing in fashion field in order to keep up with the trend for 3D printing technology to be realized in all industries so that the materials and the modeling modes may be figured out. The following is the findings. The materials used most in 3D printing in fashion field are PA, PLA, TPU, multi-material, ABS and metal. PA, TPU and Multi-material have so much excellent flexibility and strength that they are widely used for garment, shoes and such fashion items as bags. But PLA, ABS and metal are scarcely used for garment because PLA is easily biodegradable in the air, ABS generates harmful gas in the process of manufacture and metal is not flexible, while all of these three are partly used for shoes and accessories. The modeling modes mainly applied for 3D printing in fashion field are SLS, SLA, FDM and Polyjet. SLS, which is of a powder-spraying method, is used for making 3D textile seen just like knitting. Polyjet method, which has higher accuracy and excellent flexibility, can be used for expressing diverse colors, and accordingly it is used a lot for high-quality garment, while SLA and FDM method are found to be mostly used for manufacturing shoes and accessories rather than for making garment because they are easily shrunk to result in deformation.

• 한국전자통신학회논문지
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• 제9권12호
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• pp.1415-1420
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• 2014

3D 프린터는 3D도면을 입력받아 적층가공 방식으로 재료를 쌓아 원하는 제품을 제작하는 프린터이다. 3D 프린터는 다양한 입체 제품을 출력할 수 있고, 짧은 시간 내에 제품 출력이 가능하여 다양한 분야에서 사용되고 있다. 이러한 3D 프린터는 다양한 종류의 출력방식과 재료가 있는데 본 논문에서는 이중 ABS(Acrylonitrile Butadiene Styrene)수지를 녹여 쌓는 FDM(Fused Deposition Modeling)방식을 고려한다. 이 방식을 사용한 3D 프린터는 고온에서 제품을 출력하여 짧은 시간 내에 냉각이 진행되는데, 이 과정에서 출력물의 크기나 주변 환경의 상태에 따라서 휘어짐 현상이 발생한다. 이러한 휘어짐 현상을 최소화하기 위해 현재 사용되고 있는 방법은 온도를 적정선으로 유지해주는 방식이다. 이 방식은 온도 유지를 위한 추가적인 장비가 필요하여 본 논문에서는 휘어짐 현상을 최소화하기 위한 3D 프린팅 기법을 제안한다. 제안된 방식은 제품의 최초설계 시 휘어짐 위치를 고려하여 적당한 구멍(홈)을 생성시켜 출력하는 방법을 기반으로 한다. 제안된 방법에 대한 수학적 모델을 제시하고, 성능평가를 위해 일반적인 방식을 사용한 출력물과 제안된 방법으로 설계한 출력물을 측정하고 분석한다.