• 한국기계가공학회지
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• 제16권4호
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• pp.1-8
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• 2017

This paper concerns the possibility of 3D printing reverse idle gears for tractor transmission. For the purposes of this experiment, idle gears were manufactured using a SLA 3D printer, FDM 3D printer, and through machining. The accuracy of the idle gears produced in these three different ways were evaluated by the properties of their outer diameter, inner diameter, roundness, concentricity, parallelism, span, backlash, and gear grade. The tooth characteristics of the idle gears were evaluated by their profile, lead, and the pitch of the gears. The results of this experiment determined that the surface conditions created by the finishing process had a significant impact on the dimensional accuracy of the gears and the characteristics of their teeth.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.50-53
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• 2008

A design approach using a one-dimensional (1D) lumped model was studied and applied to an industrial inkjet printing head design for micro patterning on printed circuit boards. For an accurate analysis, a three-dimensional piezoelectric-driven actuator model was analyzed and its jetting characteristics were applied to 1Danalysis model. The performance of the 1D lumped model was verified by comparing measured and simulated results. The developed 1D model helped to optimize the design and configuration of the inkjet head and could be implemented in the design of multi-nozzle inkjet printing heads to improve the jetting frequency and minimize crosstalk.

• Macromolecular Research
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• 제17권3호
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• pp.197-202
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• 2009

Solution-based, direct-write patterning by an automated, computer-controlled, inkjet technique is of particular interest in a wide variety of industrial fields. We report the construction of three-dimensional (3D), micro-patterned structures by polymer inkjet printing. A piezoelectric, drop-on-demand (DOD) inkjet printing system and a common polymer, PVA (poly(vinyl alcohol)), were explored for 3D construction. After a systematic preliminary study with different solvent systems, a mixture of water and DMSO was chosen as an appropriate solvent for PVA inks. The use of water as a single solvent resulted in frequent PVA clogging when the nozzles were undisturbed. Among the tested polymer ink compositions, the PVA inks in a water/DMSO mixture (4/1 v/v) with concentrations of 3 to 5 g/dL proved to be appropriate for piezoelectric DOD inkjet printing because they were well within the proper viscosity and surface tension range. When a dot was printed, the so-called 'coffee-ring effect' was significant, but its appearance was not prominent in line printing. The optimal polymer inkjet printing process was repeated slice after slice up to 200 times, which produced a well-defined, 3 D micro-patterned surface. The overall results implied that piezoelectric DOD polymer inkjet printing could be a powerful, solid-freeform, fabrication technology to create a controlled 3D architecture.

• 한국정밀공학회지
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• 제23권7호
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• pp.168-176
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• 2006

Nowadays, Three dimensional printing (3DP) technique that is one of solid freeform fabrication (SFF) technology has been notable issue, and has been applied by various fields. The SFF system can fabricate three dimensional objects of solid freeform with high speed and low cost using ink jet printing technology. In this research, a SFF system to analyze 3DP process technology is developed. We applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm and minimized position error to the developed SFF system. We analyzed and optimized process variables such as jetted volume, layer thickness, powder bed and so on experimentally. Also. the dimensional error of a developed SFF system is evaluated. Finally, the feasibility of application to bio manufacturing is presented through successful fabrication of teeth and cranium model.

• 대한기계학회논문집A
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• 제41권9호
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• pp.839-844
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• 2017

최근 3차원 프린팅 기술은 비약적으로 발전하여 쾌속조형기술의 대명사가 되고 있다. FDM 방식의 3D프린터는 쾌속조형에 사용되는 가장 일반적인 프린터이지만, 열에 취약하고, 출력물의 표면이 매끄럽지 못하는 등의 문제를 가지고 있다. 본 논문에서는 FDM방식의 3D프린터로 ABS재질의 시편을 제작하였고, 아세톤에 시편을 담그는 방식으로 후처리를 수행하였다. 공정시간을 변수로 후처리를 진행하였으며, 처음 5초의 후처리 시간동안에는 시편의 표면조도가 급격하게 개선되는 결과를 획득하였으며, 5초 이후에는 표면조도의 변화정도가 미미하였다. 또한, 이러한 후처리 공정은 적지만 시편의 인장강도와 파단변형률을 상승시키는 결과를 나타내었다.

• 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.

• 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.

• 한국기계가공학회지
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• 제15권2호
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• pp.104-110
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• 2016

The process of three-dimensional (3D) printing (also known as "rapid prototyping" and "additive manufacturing") uses computer-created digital models to produce 3D objects with a desired shape by stacking materials through a layer-by-layer process. The industrial potential and feasibility of 3D printing technology were recently highlighted in President Obama's State of the Union address in 2013. Since his speech, worldwide investment in and attention toward 3D printing technology have increased explosively. In addition, a number of 3D printing technology-based start-up companies have been established and evaluated as emerging enterprises making successful business models. In this paper, successful start-up companies (domestic and overseas) based on 3D printing technology will be reviewed.

• 한국결정성장학회지
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• 제29권6호
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• pp.345-351
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• 2019

디지털 잉크젯 프린팅 기술은 고해상도, 빠른 인쇄 속도, 높은 잉크 효율과 같은 장점과 함께 다양한 소재 적용이 용이하여 반도체, 디스플레이, 세라믹 타일 등의 산업 분야에서 주목을 받고 있다. 최근에는 전통적인 잉크 소재에서 벗어나 우수한 내열성, 내광성, 내화학성 등을 보이는 기능성 소재도 잉크젯 프린팅 공정에 적용하려는 시도가 활발히 진행되고 있다. 특히 2차원 인쇄뿐만 아니라 3차원 적층인쇄에 관한 연구도 시작되고 있으며 이를 위해서는 토출되는 잉크의 유변학적 물성과 프린트되는 기판과의 상호작용를 제어하는 것이 필수적이다. 본 연구에서는 나노 실리카 입자가 포함된 광경화성 세라믹 잉크를 합성하고 잉크의 물성과 프린팅 기판의 표면특성을 제어하였다. 나노 실리카 입자가 포함된 광경화성 세라믹 잉크의 퍼짐현상을 억제하고 기판과의 접촉각 특성을 개선함으로써 결과적으로 프린팅 해상도 및 적층성을 향상시켰으며 잉크젯 프린팅을 이용한 광경화 나노 실리카 잉크의 3D 프린팅에 대한 가능성을 확인하였다.

• Imaging Science in Dentistry
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• 제34권1호
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• pp.13-18
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• 2004

Purpose : This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Materials and Methods: Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works /sup TM/ 3.0) and RP model fabrications were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. Results: There were relative error percentage in absolute value of 0.97, 1.98,3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. Conclusion: These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.