• Title, Summary, Keyword: pot life

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Improvement of Pot Life in the Epoxy Resin-based Adhesive Formulation by Size Control and Coating of Curing Accelerator Powders (경화촉매 분말의 입도조절 및 표면코팅에 의한 에폭시 레진 기반 혼합조성의 상온 보관특성 개선)

  • Lee, Jun-Sik;Hyun, Chang-Yong;Lee, Jong-Hyun
    • Journal of Korean Powder Metallurgy Institute
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    • v.15 no.2
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    • pp.119-124
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    • 2008
  • To increase pot life in the formulation mixed with bisphenol F epoxy resin, anhydride-based curing agent, and imidazole-based curing accelerator powders as a paste material for high-speed RFID chip bonding, size variation of the imidazole-based powders and a coating method of the powders were adopted in this study. In experiment with regard to the size variation, the pot life was not outstandingly increased. Through the idea using the coating method, however, the pot life was increased up to 4.25 times in comparison with the addition of initial imidazole-based powders. Consequently, successive bonding of RFID chip could be performed with very short time of 5sec using the suggested formulation having improved pot life.

Pot Life of Structural Adhesives for FRP Composite Used in Strengthening RC Members (구조보강용 FRP 함침·접착수지의 사용가능시간 분석)

  • Choi, Ki-Sun;You, Young-Chan;Kim, Keung-Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.3
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    • pp.191-198
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    • 2008
  • Pot life of two-component adhesives such as epoxy resin used in saturating FRP composite is defined as a certain time periods which can guarantee the bond performance and workability of epoxy resin. Therefore, adhesion procedure in strengthening RC members should be completed before chemical hardening is going on at job site. It has been known that there are two types of test method to evaluate the pot life of structural adhesive based on apparent viscosity or temperature change. This study is to verify the test methods how to assess pot life of structural adhesive for FRP composites by means of changing in apparent viscosity and means of exothermic reaction temperature proposed in existing test standards. Results of each test method were compared and analyzed, and reasonable test and evaluation method were suggested.

Environmental Impact and Water Foot Print Assessment of Pot Bearing Using Life Cycle Assessment (LCA) (LCA를 이용한 교량용 포트받침 환경영향 및 물발자국 분석)

  • Park, Jihyung;Wie, Daehyung;Ko, Kwanghoon;Hwang, Yongwoo
    • Journal of The Korean Society of Civil Engineers
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    • v.38 no.6
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    • pp.851-857
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    • 2018
  • In this research, LCA analysis of the manufacturing process of pot bearing for fixed, movable in all directions, movable in one direction was carried out to analyze the environmental load using the LCA methodology. Especially, the water footprint that has been and issue in recent years was analyzed. As a result of LCA, it was analyzed that the contribution of the plate was more than 64.2% in all of the six impact categories in the case of fixed pot bearing base, and more than 94% in the category of resource depletion and photochemical oxidant creation. In the case of all direction pot bearing and one direction pot bearing, the contribution of PTFE was the highest in the global warming and stratospheric ozone depletion, and the contribution by the plate was higher in the other impact categories. The water footprint of each type of pot bearing was analyzed as $22.4m^3\;H_2O\;eq/kg$ for one direction pot bearing, $17.1m^3\;H_2O\;eq/kg$ for fixed pot bearing, and $14.1m^3\;H_2O\;eq/kg$ for all direction pot bearing. As a result of life cycle analysis, the contribution of water use in manufacturing was more than 65% in all three types. The results of this study can be used as basic data for decision making in construction method and material selection of bridges in the future.

Pot Life Assessment and Mechanical Property of Fast Curing Polyurethane Developed with Eco-friendly Pre-polymer

  • Joseph, Jessy;Moon, Junho;Kong, Tae Woong;Kim, Dong Ho;Oh, Jeong Seok
    • Elastomers and Composites
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    • v.55 no.1
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    • pp.13-19
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    • 2020
  • 4,4'-Methylenebis(2-chlorobenzenamine) (MOCA)-free fast curing polyurethanes were prepared. In this study, the processibility of a fast curing polyurethane system was characterized by assessing the pot life. The obtained pot life of the polyurethane was 6-8 s, indicating that this prepolymer-curative system is appropriate for ribbon flow casting. The influence of the NCO index on the viscosity and mechanical properties was evaluated. The viscosity, tensile strength, tear strength, and hardness of the as-prepared polyurethanes showed an increasing trend, with an increase in the NCO index, whereas the elongation at break increased initially and then decreased with an increase in the NCO index. The gel fraction and crosslink density showed a direct correlation with the NCO index, which substantiated the improved mechanical properties at the higher NCO index. The coefficients of friction and abrasion deteriorated with an increase in the NCO index.

Effect of Germanium Foliar Spray Application on Growth Characteristics and Germanium Absorption in Rice (게르마늄 엽면살포가 벼의 생육과 게르마늄 흡수에 미치는 영향)

  • Park, Jong-Hwan;Seo, Dong-Cheol;Kim, Seong-Heon;Lee, Choong-Heon;Lee, Seong-Tea;Choi, Jeong-Ho;Kim, Hong-Chul;Ha, Yeong-Rae;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.4
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    • pp.649-656
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    • 2012
  • To obtain the basic information for agricultural utilization of germanium (Ge), the growth characteristics and Ge absorption in rice plant were investigated under different Ge concentrations by foliar spray application. The Ge concentrations were treated with 0 (control), 10, 20, 40 and $80mg\;L^{-1}$ in pot (1 5000$^{-1}$ a), respectively. The Ge absorption rate in rice by foliar spray application with $80mg\;L^{-1}$ in pot was higher in the order of leaf (5.75%) > stem (4.52%) > root (<0.01%). By foliar spray application, the Ge content in rice was higher in the order of $80mg\;L^{-1}$ > $40mg\;L^{-1}$ > $20mg\;L^{-1}$ > $10mg\;L^{-1}$. When rice was treated with $80mg\;L^{-1}$ of Ge, the Ge content in rice grain was higher in the order of rice bran ($0.21mg\;pot^{-1}$) $\gg$ brown rice ($0.04mg\;pot^{-1}$) ${\geq}$ polished rice ($0.03mg\;pot^{-1}$). By foliar spray application, the Ge uptake in rice bran was higher than that in other parts. Therefore, optimum Ge concentration by foliar spray application was $80mg\;L^{-1}$ in pot based on the results from the Ge treatments.

Characterization of Fluxing and Hybrid Underfills with Micro-encapsulated Catalyst for Long Pot Life

  • Eom, Yong-Sung;Son, Ji-Hye;Jang, Keon-Soo;Lee, Hak-Sun;Bae, Hyun-Cheol;Choi, Kwang-Seong;Choi, Heung-Soap
    • ETRI Journal
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    • v.36 no.3
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    • pp.343-351
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    • 2014
  • For the fine-pitch application of flip-chip bonding with semiconductor packaging, fluxing and hybrid underfills were developed. A micro-encapsulated catalyst was adopted to control the chemical reaction at room and processing temperatures. From the experiments with a differential scanning calorimetry and viscometer, the chemical reaction and viscosity changes were quantitatively characterized, and the optimum type and amount of micro-encapsulated catalyst were determined to obtain the best pot life from a commercial viewpoint. It is expected that fluxing and hybrid underfills will be applied to fine-pitch flip-chip bonding processes and be highly reliable.

Application of Subirrigation Using Capillary Wick System to Pot Production

  • Lee, Chi-Won;So, In-Sup;Jeong, Sung-Woo;Huh, Moo-Ryong
    • Journal of agriculture & life science
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    • v.44 no.3
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    • pp.7-14
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    • 2010
  • Alternative subirrigation way, capillary wick system (CWS) was tested to reduce labor cost, waste water, contamination of ground water, and use of fungicide compared to overhead irrigation system (OIS). CWS helped reduce remarkably the working hours for watering from 4 hours in OSI to just 5 minutes. Labor cost was saved 98% in CWS compared to OIS. By the physical characteristics of various growing media, 1 coconut coir+2 perlite (v/v) mixture was selected because it had an ideal distribution of three phase, e.g. 1 solid: 1 liquid: 2 gas phase. Medium mixture containing scoria had so high bulk and particle density to hurt root. In bark-containing medium, the liquid phase and the percent saturation of liquid phase with time elapsed was lower than that of other mixture. It meant that the mixture contained very low level of water. Application of CWS for cyclamen pot production played an important role in reducing the incident of fusarium wilt symptom from 18% in conventional over watering system to 4%. Cyclamen pot irrigated by capillary wick had shorter petiole and more leaves than those by overhead watering. As a result, this system was highly beneficial to get uniform pot products with high quality. It improved water and nutrient solution efficiency relative to conventional overhead irrigation system (OIS).

Encapsulation of an 2-methyl Imidazole Curing Accelerator for the Extended Pot Life of Anisotropic Conductive Pastes (ACPs) (이방 도전성 페이스트의 상온 보관성 향상을 위한 Imidazole 경화 촉매제의 Encapsulation)

  • Kim, Ju-Hyung;Kim, Jun-Ki;Hyun, Chang-Yong;Lee, Jong-Hyun
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.4
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    • pp.41-48
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    • 2010
  • To improve the pot life of one-part in-house anisotropic conductive paste (ACP) formulations, 2-methyl imidazole curing accelerator powders were encapsulated with five agents. Through measuring the melting point of the five agents using DSC, it was confirmed that a encapsulation process with liquid-state agents is possible. Viscosity of ACP formulations containing the encapsulated imidazole powders was measured as a function of storage time from viscosity measurements. As a result, pot life of the formulations containing imidazole powders encapsulated with stearic acid and carnauba wax was improved, and these formulations indicated similar curing behaviors to a basic formulation containing rare imidazole. However, the bondlines made of these formulations exhibited low average shear strength values of about 37% level in comparison with the basic formulation.

Evaluation of Entomopathogenic Nematodes against Armyworm, Pseudaletia separata on Tall Fescue, Festuca arundinacea (톨페스큐에서 곤충병원성선충의 멸강나방에 대한 효과 검정)

  • Jung, Young Hak;Kim, Jong Ju;You, Eun Ju;Lee, Chae Min;Choo, Ho Yul;Lee, Dong Woon
    • Weed & Turfgrass Science
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    • v.2 no.3
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    • pp.312-317
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    • 2013
  • The armyworm, Pseudaletia separata was occurred suddenly in a golf club in Namhae, Gyeongnam province in 2013. Thus, pathogenicity of seven species of entomopathogenic nematodes (Steinernema carpocapsae GSN1 strain, S. glaseri Dongrae strain, S. longicaudum Nonsan strain, S. monticolum Jiri strain and S. siamkayai, Heterorhabditis sp. Gyeongsan strain, and H. bacteriophora Hamyang strain) was evaluated against armyworm on tall fescue in pot and golf course to control this pest environmentally friendly. The pathogenicity against P. separata larvae was significantly different depending on nematode species. The corrected mortality of fifth instar of P. separata was 100% in the treatment with S. carpocapsae GSN1 in 7 days in tall fescue pot. However, there was not different in the mortality of fifth instar of P. separata (80 to 100%) at the rate of 385 to 6,160 infective juveniles (Ijs) ($=2.5{\times}10^2$ to $4{\times}10^5Ijs/m^2$) of S. carpocapsae GSN1 strain in each pot. Corrected mortality of P. separata was 65 and 60% at the rate of $10^5Ijs/m^2$ of S. carpocapsae GSN1 and S. longicaudum Nonsan strain, respectively in the tall fescue of golf course.