• Title/Summary/Keyword: Low binders

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Characteristics of Pyrophyllite Aggregate fired at Low Temperature(II) (저온소성 납석질 벽돌의 특성에 관한 연구(저온소성 ladle용 벽돌의 개발연구 제이보))

  • 지응업;한기성;최상욱
    • Journal of the Korean Ceramic Society
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    • v.12 no.2
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    • pp.3-9
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    • 1975
  • The continuous grading method of pyrophyllite particles was adopted to prepare the refractories for ladle. The optimum conditions of fabrication adjusting the binders, the amount of water, the forming pressure and the firing temperature were investigated. The various properties, such as strength, density, porosity, thermal shock, corrosion resistance to slag were measured and compared with properties of ladle bricks presently used at local steel plants. The specimen studied in the present investigation showed a rather superior properties to theconventional product available locally.

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Low-Temperature Solution Polymerization of Vinyl Acetate in Methanol Using 4,4시-Azobis(4-cyanovaleric acid) in Methanol (4,4시-아조비스(4-시아노발레릭산)을 이용한 아세트산비닐의 메탄올계 저온 용액중합)

  • Kwak, Jin-Woo;Lyoo, Won-Seok
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.52-54
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    • 2003
  • Poly(vinyl alcohol) (PVA) obtained by the saponification of poly(vinyl ester) is a linear semicrystalline polymer; these polymers have been widely used as fibers for clothes and industries, binders, films, membranes, medicines for drug delivery system, and cancer cell-killing embolic materials. PVA fibers have high tensile and compressive strength, tensile modulus, and abrasion resistance because of the highest crystalline lattice modulus. (omitted)

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A Viscoplastic Constitutive Model Based on Overstress Concept with Time-Temperature Superposition Principle (시간-온도 중첩이론을 적용한 아스팔트 바인더의 점소성 구성 모형)

  • Yun, Tae-Young;Ohm, Byung-Sik;Yoo, Pyeong-Jun;Kim, Yeon-Bok
    • International Journal of Highway Engineering
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    • v.14 no.5
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    • pp.75-83
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    • 2012
  • PURPOSES: Suggestion of asphalt binder constitutive model based on time-temperature superposition principle and overstress concept in order to describe behavior of asphalt binders. METHODS: A series of temperature sweep tests and multiple stress creep and recovery(MSCR) tests are performed to verify the applicability of time-temperature superposition principle(t-Ts) and to develop viscoelastoplastic constitutive equation based on overstress concept. For the tests, temperature sweep tests at various high temperature and various frequency and MSCR test at $58^{\circ}C$, $64^{\circ}C$ $70^{\circ}C$, $76^{\circ}C$, and $82^{\circ}C$ are performed. From the temperature sweep tests, dynamic shear modulus mastercurve and time-temperature shift function are built and the shift function and MSCR at $58^{\circ}C$ are utilized to determine model coefficients of VBO model. RESULTS: It is observed that the time-temperature shift function built at low strain level of 0.1% is applicable not only to 1.0% strain level temperature sweep test but also maximum 500,00% strain level of MSCR test. As well, the modified VBO model shows perfect prediction on MSCR measured strain at the other temperatures. CONCLUSIONS: The Time-temperature superposition principle stands hold from very low strain level to very high strain level and that the modified VBO model can be applicable for various range of strain and temperature region to predict elastic, viscoelastic, and viscoplastic strain of asphalt binders.

The Improvement of the Opacity and Printing Strength of Fancy Paper Overlaid Plywood

  • Kuo Lan-Sheng;Perng Yuan-Shing;Wang Eugene I-Chen;Yen Chen-Fa;Kao Tsuen-Han
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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    • pp.91-98
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    • 2006
  • The purpose of this study is to investigate the opacity and printing strength of MG paper overlaid plywood. The printing strength of ink on MG paper can be evaluated effectively by a formula $E^{*2}=[(L^{*})^{2}+(a^{*})^{2}+(b^{*})^{2}]^{1/2}$ that we proposed. Higher E value indicates good printing strength of ink-on-paper. We also assess the real color of translucent printed MG paper with a formula CIE ${\bigtriangleup}E^{*}$ (color difference between a pile of same paper to be opaque and fancy paper laminated board). In addition, the color difference on paper surface caused by the color of wood-based board (bottom) can be evaluated by a formula of Pc. No. Generally, an acceptable appearance quality of fancy boards is ${\bigtriangleup}E^{*}$ <2.0 and small Pc.No. value. The experimental results showed that Japan-made MG papers -J1, J2 and J3 have better printing strength and gloss than that of Taiwan-made paper (T1). The reason for this was that Taiwan-made paper has poor printing strength and low gloss, which might be correlated to the fiber compositions in paper. Higher printing strength can be seen for short fiber containing handsheets when comparing to that of handsheets. Nonetheless, low-freeness sheets gives better printing strength than that of high-freeness sheets. High-opacity MG paper gives good opacifying effect to the fancy paper laminated wood-based boards. Comparing the surface color of 2 kinds of fancy paper laminated boards, paperboard T1 laminated with high-opacity fancy paper showed slight color difference. The same results can be seen for $??g/m^{2}$ handsheets. Higher-opacity Acacia and Eucalyptus bleached sulfate pulps (short fiber) gives higher opacifying effect on the plywood when comparing to Northan pine and Radiata pine sulfate pulps(long fiber). The former ones also showed small color differences when comparing the color differences between the color of fancy paper and laminated paper board. Additionally, the color of bottom plywood can't be shown through for the high-opacify surface paper adhered to. Besides, the PC No of the base paper laminated board is small as well. Apparently, we can add colorants to the binders for the manufscture of various handsheets ($30g/m^{2}$) with various pulp mix ratios to increase the opacity of paperboards to certain extents. When we using yellow and brown binders in paper laminated board, the color difference between Acacia and Eucalyptus handsheets overlaid boards decreasing to 2.0 (acceptable ${\bigtriangleup}E^{*}$ <2.0, hard to discern), but not much improvement for Northern and Radiata pines. Definitely, show-through defects can be discernible for lower opacity papers. In general, admirable printing strength of fancy paper by which glued to plywood can be made with high-opacity paper and colored binders techniques.

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Low Temperature Debinding Process Using Oxygen Plasma for Flexible Printed Electronics

  • Lee, Young-In
    • Journal of Powder Materials
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    • v.19 no.5
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    • pp.343-347
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    • 2012
  • In this study, an oxygen plasma treatment was used as a low temperature debinding method to form a conductive copper feature on a flexible substrate using a direct printing process. To demonstrate this concept, conductive copper patterns were formed on polyimide films using a copper nanoparticle-based paste with polymeric binders and dispersing agents and a screen printing method. Thermal and oxygen plasma treatments were utilized to remove the polymeric vehicle before a sintering of copper nanoparticles. The effect of the debinding methods on the phase, microstructure and electrical conductivity of the screen-printed patterns was systematically investigated by FE-SEM, TGA, XRD and four-point probe analysis. The patterns formed using oxygen plasma debinding showed the well-developed microstructure and the superior electrical conductivity compared with those of using thermal debinding.

characteristics of Magnesia Dam Block for Tundish Vessel in Steel Making Process (턴디쉬용 마그네시아질 댐블록의 제조와 그특성)

  • 정두화;김상모;이석근
    • Journal of the Korean Ceramic Society
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    • v.36 no.8
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    • pp.876-885
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    • 1999
  • In order to develop high performance basic dam block for tundish vessel in steel-making binders and additives on hydration and thermal characteristics of magnesiz castable refractories were studied. Crack initiation and propagation in cement bonded magnesia castables due to slaking of magnesia clinker at drying process were suppressed by using spinel clinker instead of magnesia powder. In case of Na2O$.$2CaO$.$P2O5(NC2P) bonded castable crack initiation due to slaking of magnesia clinker did not occur but bending strength at high temperature was low. Mechanical properties of NC2P bonded castable refractories at high temperature were improved by using magnesia clinker that contains low SiO2 contents.

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Property Evaluation of Low-Heat Concrete with Phosphate-PCM Composite (Phosphate-PCM계 복합물질 기반 저발열 콘크리트의 특성 평가)

  • Ki, Jun-Do;Lee, Sang-Hyun;Cho, Hong-Bum;Kim, Young-Sun;Seok, Won-Kyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.175-176
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    • 2020
  • This study aims to develop the hydration heat reducing material (powder type) to lower the heat of hydration of mass members in the extremely hot weather condition. In this study, we applied the developed material to the concrete that used two kinds of binders with cement and evaluate the concrete properties with it.

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Influence of a Flexibilizer on Physical Properties of Crumb Rubber Modified Asphalt Sealants (폐타이어 고무분말 개질 아스팔트 실란트의 물리적 특성에서 유연제의 영향)

  • Kim, Jong-Seok
    • International Journal of Highway Engineering
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    • v.11 no.3
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    • pp.33-40
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    • 2009
  • The use of the crumb rubber as an asphalt binder modifier may contribute to road maintenance and repair. The adhesion properties of the crumb rubber modified asphalt (CRMA) sealant have attracted interest due to brittle and adhesion failure of asphalt binders at low temperatures. In this study, the influence of a flexibilizer as a modifier for CRMA at low temperatures was investigated. Their properties were measured using the penetration, the softening point, the tensile and tensile adhesion tests at low temperature. The tensile adhesion strength and the strain of CRMAs were increased with increasing ductile deformation of the CR and the asphalt binder in the flexiblizer modified CRMAs. It was found that the flexibilizer concentration was an important factor for tensile and adhesion properties of CRMAs at low temperatures.

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Fundamental characteristics of high early strength low heat concrete according to mineral binder and high early strength material combination (광물질 결합재 및 조강형 재료 조합에 따른 조강형 저발열 콘크리트의 기초적 특성)

  • Kim, Kyoungmin;Son, Hojung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.1
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    • pp.27-32
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    • 2014
  • This study analyzed the fundamental characteristics of concrete according to a ternary system mixing in order to reduce hydration heat of mass concrete and to improve early age strength. The results are as follows. The fluidity of unconsolidated concrete satisfied the target scope regardless of the binder conditions. When the replacement ratio between FA and BS increased, the slump of low heat-A mix and low heat-B mix increased, and air content was not affected by the change of binders. As for setting time, low heat cement mix had the fastest regardless of W/B, and high early strength low heat mix achieved 6 hours' reduction compared with low heat-B mix at initial set, and 12 hours' reduction at the final set respectively. As for the simple hydration heat, the low mix peak temperature was the highest and low heat-B mix had the lowest temperature. And high early strength low heat mix was similar with that of low heat-B. The compressive strength of hardened concrete had similar strength scope in all mixes except for low heat-B mix at early ages, and had unexceptionally similar one without huge differences at long-term ages.

A Study on Sulfonated Fluorenyl Poly(ether sulfone)s as Catalyst Binders for Polymer Electrolyte Fuel Cells (고분자 전해질 연료전지 촉매층 바인더를 위한 Sulfonated Fluorenyl Poly(ether sulfone)에 관한 연구)

  • Cho, Won Jae;Lee, Mi Soon;Lee, Youn Sik;Yoon, Young Gi;Choi, Young Woo
    • Journal of the Korean Electrochemical Society
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    • v.19 no.2
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    • pp.39-44
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    • 2016
  • Oxygen reduction reaction in the fuel cell (ORR) plays a dominant role in the overall reaction. In addition, the low compatibility between the membrane and the binder consisted of different materials, greatly reduces the efficiency of the fuel cell performance. In view of these two problems, geometrically modified copolymers with 9.9_Bis (4-hydroxyphenyl) were synthesized via condensation reaction instead of conventional biphenol and were adopted as hydrocarbon ionomer binders. By utilizing these binders, two kinds of MEAs using fluorinated Nafion membrane and hydrocarbon based membrane were manufactured in order to electrochemical performance evaluation. With current-voltage curves, there was no significant difference in the 0.6 V when two types of membrane were applied. Also, tafel slope became considerably lower as compared to the Nafion membrane. Thus, it is determined that the new hydrocarbon binder is expected to contribute the improvement in performance of fuel cells.