• Title/Summary/Keyword: Direct printing

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Flow Stress Determination of Johnson-Cook Model of Ti-6Al-4V Material using 3D Printing Technique (3D 프린팅으로 제작한 Ti-6Al-4V 재료의 Johnson-Cook 모델의 유동 응력 결정)

  • Park, Dae-Gyoun;Kim, Tae-Ho;Jeon, Eon-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.4
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    • pp.64-69
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    • 2018
  • This paper investigates the compressive deformation behavior of direct metal tooling (DMT), processing titanium alloy (Ti-6Al-4V) parts under high strain loading conditions. Split Hopkinson Pressure Bar (SHPB) experiments were performed to determine the flow stress and the coefficients of the Johnson-Cook model. This model is described as a function of strain, strain rate, and temperature. SHPB experiments were performed to characterize the deformation behavior of specimens made with 3D printers, using Ti-6Al-4V material under high temperature and dynamic loading.

Stock Preparations for the Opacity Improvement of Printing Paper (인쇄용지의 불투명도 향상을 위한 지료조성)

  • 최성훈;김봉용
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.1
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    • pp.1-9
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    • 2000
  • This study was carried out to improve the opacity of printing paper. Conventional filler loading enhanced the opacity of paper, but subsequently caused reduction of paper strength of paper. We try to seek a new filler loading method so-called beater loading that enhances opacity of paper as well as sustained desire strength. In our experiment, comparing to direct loading method, the beater loading method enhanced 0.8% of opacity and 0.2% of brightness. This also decreased the rates of strength reduction of paper. Therefore, the results obtained in this study indicated that beater loading was a very effective method to improve the opacity of paper while not to decreased so much of paper strength.

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Fabrication and Application of Graphene Composite with Various Modifications (다양한 변화가 가능한 그래핀 복합체 제작 및 응용)

  • Park, Jongsung;Kim, Dong-Su;Kim, Ji-Kwan
    • Journal of Sensor Science and Technology
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    • v.29 no.3
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    • pp.201-204
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    • 2020
  • In this study, we fabricated and evaluated graphene composite based 3D scaffolds and planar films. The hybrid composite was prepared by mixing a calculated amount of graphene nanopowder and polydimethylsiloxane in tetrahydrofuran solution. The hybrid composite is easy to manufacture into various forms using direct printing technology or a pressing method. A 3D scaffold structure was prepared at ambient temperature with a flow rate of 240 mm/min. The nozzle pressure was maintained at 350 kPa by adjusting the viscosity of the composite material. The planar film was prepared at different thicknesses using a roll-to-roll equipment. The prepared hybrid nanocomposites were evaluated to investigate their electrical properties according to temperature and mechanical deformation. The obtained results were consistent with each other. Therefore, it can be used effectively as sensors through shape definition.

Estimation of Carbon Footprint in Cherry-tomato Production System and Carbon Labelling in Agriculture Product (시설방울토마토의 생산과정에 있어 탄소배출량 산정과 농산물의 탄소라벨링)

  • Kim, Young-Ran;Yoon, Sung-Yee
    • Korean Journal of Organic Agriculture
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    • v.19 no.3
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    • pp.291-308
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    • 2011
  • This study was carried out to estimate carbon footprint and to establish of LCA of cherry-tomato production system. I have case study in cultivate cherry tomato (1 kg) calculate in carbon foot print. LCA carried out to estimate carbon foot print and to establish of LCI (life cycle inventory) database of cherry tomato production system. The data is from Research of Farmer's income in 2007 (RDA, 2008), and used Pass (4.1.3) program. The value of fertilizer, amount of pesticide input were show the environmental effect and direct emission. Carbon foot printing in agriculture guarantee the choice right th consumer th choose the row carbon goods. Its can make to strengthen of agriculture and food industry's reduction effort of $CO_2$. Nowadays consumer request food's safety and environment friendly process. Carbon foot printing needs consumer's relief and incentives.

Survey of Colorfastness of Korean Silk Fabrics (국내산 견직물의 염색견뢰도조사)

  • G. Freddi
    • Journal of Sericultural and Entomological Science
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    • v.32 no.1
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    • pp.68-72
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    • 1990
  • The color fastness of Korean silk fabrics was measured in this investigation. The sample fabrics under examination were divided into four groups, according to the processing cycle: 1) Plain dyeing(A-C) : 2) Yarn dyeing(D;E=Knitted fabric) ; 3) Direct printing(F-H) ; 4) Discharge Printing(I-P) : The following result can be obtained. Among the samples examined, both the plain-dyed(brilliant colours) and discharge-printed (put-in colours) fabrics show lower values of water, perspiration and ironing color fastness compared with those recommended by International Organization for Standardization(I. S. O.)

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Mechanical Property of Photocurable Hydrogel Fiber by Light Intensity (빛의 강도에 따른 광경화성 하이드로겔 섬유의 기계적 물성)

  • Lee, Sangmin;Chu, Bokyeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.10
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    • pp.38-43
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    • 2021
  • Photocurable hydrogels are widely used as 3D printing materials in tissue engineering (e.g., scaffold fabrication) as well as optical fibers (or optical sensors) materials. Photocurable hydrogels can control optical and mechanical properties such as chemical or fabrication conditions. In previous research, we introduced a new 3D printing method to fabricate a freestanding overhanging hydrogel structure without supporting structure. This study was measured and analyzed the difference of the mechanical properties of the photocurable hydrogel according to the light intensity using a micro tensile tester. In practically, it was difficult to perform a direct tensile test on a micro (less than 1 mm) size fiber. In this study, the tensile test of the hydrogel fibers could be measured simply and repeatedly using a paper carrier.

Investigating the Effect of Photoinitiator Types and Contents on the Photocuring Behavior of Photocurable Inks and Their Applications for Etching Resist Inks (광개시제 종류 및 함량에 따른 광경화형 잉크의 광경화 특성과 인쇄회로기판용 에칭 레지스트 소재로의 적용성 연구)

  • Bo-Young Kim;Subin Jo;Gwajeong Jeong;Seong Dae Park;Jihoon Kim;Eui-Keun Choi;Myong Jae Yoo;Hyunseung Yang
    • Applied Chemistry for Engineering
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    • v.34 no.4
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    • pp.444-449
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    • 2023
  • As electronic devices become smaller and more integrated, the demand for manufacturing thin, flexible printed circuit boards (FPCBs) has increased. Although FPCBs are conventionally manufactured by a photolithography method using dry film resist, this process is complicated, and the mask is specifically designed to obtain the precision of the desired circuit line width. In this regard, manufacturing FPCBs with fine patterns through the direct printing method of photocurable inks has gained growing attention. Since the manufacturing process of FPCBs is based on the direct printing method that includes etching and stripping processes utilizing acid and basic chemicals, controlling the adhesion strength, the etching resistance, and the strippability of photocured inks has drawn a lot of attention for the fabrication of fine patterns through photocurable inks. In this study, acrylic ink with various types and contents of the photoinitiator was prepared, and the curing behavior was analyzed. Also, the adhesion strength, etching resistance, and strippability were analyzed to evaluate the applicability of developed photocurable etching resist inks.

A Study about Development of Environment Printing Technology and $CO_2$ (환경 인쇄 기술의 발전과 인쇄물의 $CO_2$ 발생량에 관한 연구)

  • Lee, Mun-Hag
    • Journal of the Korean Graphic Arts Communication Society
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    • v.30 no.3
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    • pp.89-114
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    • 2012
  • For as to world, the concern about the environment problem is enhanced than any other time in the past because of being 21 century. And the environment problem is highlighted as the world-wide issue. The time of the environment problem intimidates the alive of the mankind and presence of an earth over the time. It becomes the essentiality not being selection in the personal living or the economical viewpoint now to prepare for the climatic modification. As to the company management, the green growth period which it excludes the environment management considering an environment, cannot carry on the company the continued management comes. That is, in the change center of the management paradigm, there is the environment management. Nearly, the greenhouse gas which the publication industry is the environmental toxic material like all industries is generated. The greenhouse gas is ejected in the process of running the manufacturing process and print shop of the various kinds material used as the raw material of the book. Particularly, the tree felling for getting the material of the paper is known to reach the direct influence on the global warming. This study does according to an object it considers and organizes the environment parameter based on this kind of fact as to the publication industry. And it is determined as the reference which is used as the basic materials preparing the case that carbon exhaust right transaction(CAP and TRADE) drawing are enforced in all industries and is sustainable the management of the publication industry and reduces the environmental risk among the company many risk management elements and plans and enforces the publication related policy that there is a value. In the printing publication industry, this study tried to inquire into elements discharging the environmental pollutant or the greenhouse gas. Additionally, in the printed publication production process, it tried to inquire into the effort for an environment-friendly and necessity at the printing paper and the printers ink, regarded as the element discharging the greenhouse gas all kinds of the printing materials, operation of the print shop and all kinds of the machines and recycle process, and etc. These considerations make these industrial field employees aware of the significance about a conservation and environmental protection. They try to give a help in the subsequent study producing quantitatively each environmental parameter emission of green house gas. This makes the calculation of the relative $CO_2$ output reproached ultimately possible. Meanwhile, in a sense, many research protects and improving an environment in connection with the contents of research at the printing publication industrial field is in progress. There will be the voluntary human face that it has to protect an environment but this can not do by the outside factor according to all kinds of environment related law and regulation. Anyway, because of acting on company management as the factor of oppression, the increase of this environment-related correspondence cost could know that the research that the environment loading relates with a procurement and development, environment management system introduction, quality control standard, including, normalizing including a material, and etc. through the part of the effort to reduce the cost low was actively in progress. As to the green growth era, as follows, this paper prescribed the subject and alternative of the print publication industry. It is surrounded by the firstly new digital environment and the generation of the subject. And secondly the printing industry is caused by the point of time when the green growth leaves by the topic which is largest in the global industry and it increases. The printing publication industry has to prepare the bridgehead for the environment-friendly green growth as the alternative for this resolution with first. The support blown in each industry becomes the obligation not being selection. Prestek in which the print publishing was exposed to spend many energies and which is known as the practice of the sustainable print publishing insisted that it mentioned importance of the green printing through the white pages in 2008 and a company had to be the green growth comprised through the environment-friendly activity. The core management for the sustainable printing publication industry presented from Presstack white pages is compacted to 4 words that it is a remove, reduce, recover, and recycle. Second, positively the digital printing(POD) system should be utilized. In the worldwide print out market, the digital printing area stops at the level of 10% or so but the change over and growth of the market of an analog-to-digital will increase rapidly in the future. As to the CEO Jeff Hayes of the Infoland, the offset print referred to that it of the traditional method got old and infirm with the minor phase of the new printing application like the customer to be wanted publication and the print of the digital method led the market. In conclusion, print publishers have to grasp well the market flow in the situation where a digitalization cannot be generalized and a support cannot avoid. And it keeps pace with the flow of the digital age and the recognition about the effort for the development and environment problem have to be raised. Particularly, the active green strategy is employed for the active green strategy.

Comparison of Surface Characteristics According to 3D Printing Methods and Materials for the Fabrication of Microfluidic Systems (미세유체시스템 제작을 위한 3D 프린팅 방식 및 소재 별 표면특성 비교)

  • Bae, Seo Jun;Im, Do Jin
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.706-713
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    • 2019
  • In this study, basic research was conducted to provide guidelines for selecting printers and materials suitable for each application case by analyzing 3D printing method and surface characteristics of materials suitable for microfluidic system. We have studied the surface characteristics according to the materials for the two typical printing methods: The most commonly used method of Fused Deposition Modeling (FDM) printing and the relatively high resolution method of Stereolithography (SLA) printing. The FDM prints exhibited hydrophilic properties before post - treatment, regardless of the material, but showed hydrophobic properties after post - treatment with acetone vapor. It was confirmed by the observation of surface roughness using SEM that the change of the contact angle was due to the removal of the surface structure by post-treatment. SLA prints exhibited hydrophilic properties compared to FDM prints, but they were experimentally confirmed to be capable of surface modification using hydrophobic coatings. It was confirmed that it is impossible to make a transparent specimen in the FDM method. However, sufficient transparency is secured in the case of the SLA method. It is also confirmed that the electroporation chip of the digital electroporation system based on the droplet contact charging phenomenon was fabricated by the SLA method and the direct application to the microfluidic system by demonstrating the electroporation successfully.