• Title/Summary/Keyword: Injection materials

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Fabrication and Mechanical Properties of A356/SiCp Manufactured by Gas-Particle Co-injection Method (가스-입자 동시주입법에 의한 A356/SiCp 복합재료의 제조 및 기계적 특성)

  • Lee, Jung-Mu;Kang, Suk-Bong;Eum, Chil-Yong;Lim, Cha-Yong
    • Journal of Korea Foundry Society
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    • v.21 no.1
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    • pp.33-40
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    • 2001
  • Among the many techniques available to synthesis metal matrix composites, liquid phase processing, especially, conventional casting process such as stir-casting process is particularly attractive for their simplicity, economy and flexibility, In the present study, A356/20%SiCp composites were fabricated by gas-particle co-injection method. The gas-particle co-injection method is a modified stir-casting method and the corporation of particle could be improved by acceleration of particles due to rotation of impeller and gas purging. The microstructures and mechanical properties such as tensile properties and resistance to wear of fabricated materials were examined. Further, the particle injection mechanism in gas-particle co-injection method was discussed.

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Evaluation of Injection capabilities of a biopolymer-based grout material

  • Lee, Minhyeong;Im, Jooyoung;Chang, Ilhan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • v.25 no.1
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    • pp.31-40
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    • 2021
  • Injection grouting is one of the most common ground improvement practice to increase the strength and reduce the hydraulic conductivity of soils. Owing to the environmental concerns of conventional grout materials, such as cement-based or silicate-based materials, bio-inspired biogeotechnical approaches are considered to be new sustainable and environmentally friendly ground improvement methods. Biopolymers, which are excretory products from living organisms, have been shown to significantly reduce the hydraulic conductivity via pore-clogging and increase the strength of soils. To study the practical application of biopolymers for seepage and ground water control, in this study, we explored the injection capabilities of biopolymer-based grout materials in both linear aperture and particulate media (i.e., sand and glassbeads) considering different injection pressures, biopolymer concentrations, and flow channel geometries. The hydraulic conductivity control of a biopolymer-based grout material was evaluated after injection into sandy soil under confined boundary conditions. The results showed that the performance of xanthan gum injection was mainly affected by the injection pressure and pore geometry (e.g., porosity) inside the soil. Additionally, with an increase in the xanthan gum concentration, the injection efficiency diminished while the hydraulic conductivity reduction efficiency enhanced significantly. The results of this study provide the potential capabilities of injection grouting to be performed with biopolymer-based materials for field application.

Powder Injection Molding of Alumina Parts Using a Binder System Based in Paraffin Wax and High Density Polyethylene

  • Thomas-Vielma, P.;Cervera, A.;Levenfeld, B.;Varez, A.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.207-208
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    • 2006
  • In this experimental work, the development of a multicomponent binder system based on high density polyethylene (HDPE) and paraffin wax for Powder Injection Molding of Alumina $(Al_2O_3)$ parts was carried out. The optimum composition of the injection mixture was established through mixing torque measurements and a rheological study. The maximum powder loading was 58 vol%. The miscibility of organic components and the optimum injection temperature was evaluated by thermal characterization of binder and feedstock. The thermal debinding cycle was developed on the basis of thermogravimetrical analysis of the binder. After sintering the densities achieved were closed to 98% of the theoretical one.

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A Study on Manufacturing of LCD Prism Sheets Through Silicon Anisotropic Etching (실리콘 이방성 식각을 통한 LCD 프리즘 시트 제작 연구)

  • Jeon, Kwangseok;Ryoo, Kunkul
    • Korean Journal of Metals and Materials
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    • v.46 no.6
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    • pp.377-381
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    • 2008
  • Prism sheet of LCD BLU which depends on supply from Japan and U.S.A was studied by using Si anisotropic etching and injection molding technologies. First, the prism sheet was patterned on Si wafer through photolithography, and the best conditions of Si etching were determined through etching Si wafer with TMAH to obtain straight optimized zigzag patterns, and a cross pattern to provide light diffusion and concurrent focusing. The etch rate of TMAH was concluded to be constant for $25wt%-70^{\circ}C$ condition. Ni stamp of prism sheet was made by electrodeposition using patterned Si wafer, normal or fast H/C(Heating/Cooling) injections were carried out to fabricate prism sheet. It was known that fast H/C injection could fabricate prism sheet more accurately than normal injection. Zigzag patterns and the cross pattern showed higher transmissivity than the straight patterns because of light diffusion through diagonal direction. The fast H/C injection for zigzag patterns showed lower transmissivity than normal injection because there occurred more light diffusion through precise injection patterns, but the fast H/C injection for straight patterns showed only refraction without diffusion, causing lower transmissivity than normal injection.

Relation of weld-quality and core shape in injection molding (사출성형 시 코어 형상과 웰드품질과의 관계)

  • Lee, Gyu-Ho;Choi, Woo-Su;Noh, Keon-Cheol;Jeong, Yeong-Deug
    • Design & Manufacturing
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    • v.8 no.1
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    • pp.23-26
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    • 2014
  • The injection molding is used in more than 70% of total production of plastic products. Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but also mechanical property. In this study weld quality has been examined according to the injection processing temperature, materials and mold designs. We selected four different materials such as PA, PP, ABS and PS as experimental materials. Weld quality increased as injection processing temperature increases. It was more dependent on materials flow ability. As a result, weld quality incase of rectangular core is better than circular core.

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A Study on the Combustion Characteristics with Control Strategy and Injector Position Changes in a Lean-burn LPG Direct Injection Engine (연소제어 전략 및 분사기 위치 변경에 따른 직접분사식 초희박 LPG 엔진의 연소특성 연구)

  • Park, Cheolwoong;Park, Yunseo;Lee, Yonggyu;Oh, Seungmook;Kim, Taeyoung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.4
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    • pp.98-104
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    • 2014
  • The technologies employing spray-guided type combustion system for ultra-lean combustion direct injection engine is focused as a promising technology for satisfying emission regulations and improving fuel economy. In the present study, control and design optimization of lean-burn LPG direct injection engine was carried out with control strategy and injection position changes. Inter-injection spark ignition strategy was applied and the effect of the strategy was assessed at relatively higher load operation condition than previous researches. In order to create richer mixture in the vicinity of spark plug electrode, relative distance between the dead-end of injector and the electrode of spark plug was changed.

Effects of Injection Conditions on the Weld Line Creation in Injection Molding (사출성형 시 성형조건이 웰드라인의 생성에 미치는 영향)

  • Kim, Young-Mo;Park, Yeong-Min;Jang, Min-Kyu;Jeong, Yeong-Deug
    • Design & Manufacturing
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    • v.6 no.2
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    • pp.1-5
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    • 2012
  • Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study, ABS and PP were used as experimental materials. And weld line length, depth and strength have been examined according to the injection molding conditions. As the results of experimental studies, weld line length increased as flow rate increases for all materials. And the flow rate is most influenced to the creation of weld line length. Also weld line strength increased, as flow rate and melt temperature increase for all materials. The whole experiment results was similar to CAE analysis results.

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Effects of Injection Conditions on the Weld Line Creation in Injection Molding (사출성형시 성형조건이 웰드라인의 생성에 미치는 영향)

  • Kim, Young-Mo;Park, Yeong-Min;Jang, Min-Kyu;Jeong, Yeong-Deug
    • 한국금형공학회:학술대회논문집
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    • 2008.06a
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    • pp.115-119
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    • 2008
  • Weld line in injection molded part is one of the defects in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study, ABS and PP were used as experimental materials. And weld line length, depth and strength have been examined according to the injection molding conditions. As the results of experimental studies, weld line length increased as flow rate increases for all materials. And the flow rate is most influenced to the creation of weld line length. Also weld line strength increased, as flow rate and melt temperature increase for all materials. The whole experiment results was similar to CAE analysis results.

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A Study on the Weld Line Strength in Injection Molded Part (사출성형품의 웰드라인 강도에 관한 연구)

  • 모정혁;홍형식;류민영
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.211-216
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    • 2003
  • Weld line in injection molded part is one of the defect in injection molding process. Weld line deteriorates not only appearance quality but mechanical property. In this study weld line strength has been examined according to the injection operational conditions, materials and mold designs. PC and PP were used, and four different specimens were used in this experiment. Weld line strength decreased as injection temperature increases for PC. It was more dependent on mold temperature than injection temperature for PP Among the four different specimens, uneven thickness specimen showed the highest weld line strength.

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Effect of Multiple Injection on the Performance and Emission Characteristics of Lean Burn Gasoline Direct Injection Engines (다단분사가 초희박 GDI 엔진의 성능 및 배기에 미치는 영향)

  • Oh, Jin-Woo;Park, Cheol-Woong;Kim, Hong-Suk;Cho, Gyu-Baek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.2
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    • pp.137-143
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    • 2012
  • Currently, in order to meet the reinforced emissions regulations for harmful exhaust gas including carbon dioxide ($CO_2$) as a greenhouse gas, technologies for reducing $CO_2$ emission and fuel consumption are being developed. Gasoline direct injection (GDI) systems have the advantage of improved fuel economy and higher power output than port fuel injection gasoline engine systems. The aim of this study is to examine the performance and emission characteristics of a lean burn GDI engine equipped with spray-guided-type combustion system. Stable lean combustion was achieved with a late fuel injection strategy under a constant operating condition. Further improvement in specific fuel consumption is possible with the introduction of multiple fuel injection strategies, which also increases hydrocarbon (HC) and nitrogen oxide ($NO_x$) emissions and decreases carbon monoxide (CO) emission.