• The Journal of Advanced Prosthodontics
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• 제9권4호
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• pp.265-270
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• 2017

PURPOSE. This study is to evaluate the internal fit of the crown manufactured by CAD/CAM milling method and 3D printing method. MATERIALS AND METHODS. The master model was fabricated with stainless steel by using CNC machine and the work model was created from the vinyl-polysiloxane impression. After scanning the working model, the design software is used to design the crown. The saved STL file is used on the CAD/CAM milling method and two types of 3D printing method to produce 10 interim crowns per group. Internal discrepancy measurement uses the silicon replica method and the measured data are analyzed with One-way ANOVA to verify the statistic significance. RESULTS. The discrepancy means (standard deviation) of the 3 groups are $171.6\;(97.4){\mu}m$ for the crown manufactured by the milling system and 149.1 (65.9) and $91.1\;(36.4){\mu}m$, respectively, for the crowns manufactured with the two types of 3D printing system. There was a statistically significant difference and the 3D printing system group showed more outstanding value than the milling system group. CONCLUSION. The marginal and internal fit of the interim restoration has more outstanding 3D printing method than the CAD/CAM milling method. Therefore, the 3D printing method is considered as applicable for not only the interim restoration production, but also in the dental prosthesis production with a higher level of completion.

• 한국정밀공학회지
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• 제34권4호
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• pp.293-298
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• 2017

In this study, we developed a 3D chocolate printer and studied the conditions needed for chocolate printing. Because chocolate is a mixture of cocoa mass, cocoa butter and sugar particles, its properties vary with temperature, and care is required in melting and extrusion. A chocolate supply unit is composed of a heating block and a syringe pump. It is integrated with a 3-axis linear robot. In order to be more accurate than the existing 3D chocolate printer is, the system was configured so that the printing line width became $430{\mu}m$. Printing performance was studied according to various parameters. The condition needed for printing lines with a stable width was discovered by the experimental design method and has been confirmed by a 2D line test. These 3D printing experiments showed that it was possible to build a 3D shape with an inclination angle of up to $45^{\circ}$ without support. Further, chocolate printing of a 3D shape has been successfully verified with the developed system.

• 대한산업공학회지
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• 제41권3호
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• pp.253-258
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• 2015

The 3D printing is any of various processes for making a three dimensional object of almost any shape from a 3D model. Recently, a rapidly expanding hobbyist and home-use market has become established with the inauguration of the open-source RepRap and Fab@Home projects. However, this causes problems regarding copyright protection and usage of illegal 3D data. In this paper, we developed a 3D printing open-market system, which guarantees copyright protection using the remote 3D printing without direct distribution of 3D design data. Because most of the home-use 3D printers are FFF (Fused Filament Fabrication) based on NC code system, open-market system uses FFF 3D printers. Also, open-market system inspects the uploaded 3D model data, so the system can prevent distribution of illegal model data such as weapons, etc.

• 한국의상디자인학회지
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• 제12권4호
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• pp.207-221
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• 2010

This study aim to suggest how alter the korean traditional image design for umbrellas by sublimation transfer digital textile printing. Umbrellas are highly depend on design and made from polyester fiber which is proper item to utilize sublimation transfer digital textile printing. Sublimation transfer digital textile printing system can use computer system to create the delicate high dense images and one full layout through the hole umbrella. It can create distinctive style of design compare with former screen printing umbrella design. As a result of this study, Korean traditional images were adopted and recreated for umbrellas as the modern practical item. 7 of umbrella designs were developed and sample umbrellas could be produced in short period comparing with screen printing process. Through this study, as green printing process, sublimation transfer digital textile printing will be more applied to manufacture high quality textile products along with design development, thus it is expected as an alternative plan to leads growth of umbrella industries.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.702-708
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• 2018

3D 프린팅 기술은 기존 산업계의 생산 패러다임을 변화할 수 있는 4차 산업혁명의 주요기술로 큰 관심을 받고 있다. 건설분야의 특성으로 인해 3D 프린팅의 기술 도입이 타 산업분야에 비해 느리지만, 향후 생산인구의 감소와 생산성 및 안전도 향상 등을 위해 3D 프린팅을 활용한 건설 자동화가 필요하다. 본 연구에서는 3D 프린팅을 건설에 도입하기 위한 사전준비로서 건설 3D 프린팅 공종분류체계와 기존 표준품셈체계와의 연계방안을 제시 한다. 이를 위해 건설 및 3D 프린팅 관련 전문가 자문을 바탕으로 기존 건설 3D 프린팅 기술을 바탕으로 가상의 시나리오를 작성하였다. 시나리오에 따라 3D 프린팅 공사 수행에 필요한 16개의 공종을 도출하였다. 기존 공종분류체계와 표준품셈을 분석하고 도출된 3D 프린팅 공종을 연계하였다. 기존 분류체계와 동일한 3D 프린팅 공종도 있었으며 기존에 존재하지 않는 공종은 유사한 분류체계 하위에 추가하는 등 4가지 타입으로 구분하였다. 본 연구의 결과는 향후 3D 프린팅 공사관리 및 원가산정에 도움이 될 수 있을 것으로 기대된다. 향후 3D 프린팅 공사 수행을 통해 실질적인 품셈 산출이 필요하다.

• 한국생산제조학회지
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• 제26권1호
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• pp.100-107
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• 2017

3D printing is a technology that converts a computer-generated 3D model into a real object with additive manufacturing technology. A majority of 3D printing technologies uses one material, and this is considered a limitation. In this study, we developed a multi-material 3D printer by adopting dual resin vat and cleaning system with DLP (Digital Light Processing) 3D printing technology. The developed multi-material DLP 3D printer is composed of a manufacturing system, cleaning system, transporting system, and automatic resin recharging system. Various 3D structures were 3D printed with two materials, thus demonstrating the potential. Printing performance of the multi-material DLP 3D printer was studied by performing a comparative surface roughness test and tension test on specimens composed of one material as well as those composed of two materials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.873-878
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• 2007

Stability of high-speed roll-to-roll printing machines is one of the most important factors that are required for the printing machines to operate properly and to obtain reasonable printing performance. This paper proposes a new model for the web-tension system of a high-speed gravure printing machine considering span-length variations due to dancer rollers, and analyzes the stability of plant dynamics of the printing machine using the proposed model. Span-length variations due to dancer motions are considered for the modeling of plant dynamics in two ways; one is to include the effect of span-length variations without considering dancer inertias and viscous frictions, and the other is to include the effect of span-length variations with considering dancer inertias and viscous frictions. The stability of the plant model is analyzed for various web-speeds using the eigenvalues of the linearized model about operating points.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.22-24
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• 2004

This paper proposes a printing quality inspection system of film-type envelopment. Since the printing system is running at very high-speed (140m/min.) and the line error has very narrow width, we have to choose one-dimensional high-speed and high-resolution line scan camera. The vibration of the printing machine and the illumination environment make the inspection problem more harder. To obtain reliable inspection results, many software image processing techniques are applied and many parameters are tuned. The performance of the proposed system is proved by many simulations and long time real-plant experiments.

• 한국CDE학회논문집
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• 제21권3호
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• pp.215-223
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• 2016

The low price around 1000 USD makes consumer 3D printers as a new additive manufacturing platform for the personal manufacturing where consumers can make and sell their own products. To allow the consumers to design and manufacture their products, not only economic 3D printers but also supporting information systems for their design and manufacturing are essential. This study suggests an extended product data management (PDM) system that can support both the design and manufacturing of personal products with consumer 3D printing services. This extended PDM system helps consumer designers use advanced PDM technologies for their design and connected 3D printing services with Internet of Things (IoT) technology for realization of their products. As a result, the proposed system supports the consumer designers a seamless integrated product development and manufacturing environment supported by PDM and consumer 3D printing services.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1257-1260
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• 2007

A single-wall carbon nanotube (SWNT) transparent conductive film (TCF) was fabricated using a simple inkjet printing method. The TCF could be selectively patterned by controlling the dot size to diameters as small as $34\;{\mu}m$. In this repeatable and scalable process, we achieved 71% film transmittance and a resistance of 900 ohm/sq sheet with an excellent uniformity, about ${\pm}\;5%$ deviation overall. Inkjet printing of SWNT is substrate friendly and the TCF is printed on a flexible substrate. This method of fabrication using direct printing permits mass production of TCF in a large area process, reducing processing steps and yielding low-cost TCF fabrications on a designated area using simple printing.