금속분말 사출성형공정 중 초임계 CO2를 이용한 탈지공정에서 공용매 효과

김용호; 임종성; 이윤우; 박종구; 이창하; Yong-Ho Kim; Jong Sung Lim; Youn-Woo Lee; Jong-Ku Park; Chang Ha Lee

HWAHAK KONGHAK, Vol.41, No.1, 51-57, February, 2003

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금속분말 사출성형공정 중 초임계 CO2를 이용한 탈지공정에서 공용매 효과

Effects of Cosolvent on Supercritical CO2 Debinding in Metal Injection Molding Process

김용호 , 임종성 ^†, 이윤우 , 박종구 ¹, 이창하 ²

한국과학기술연구원 초임계유체연구실, 136-791 서울시 성북구 하월곡동 39-1
¹한국과학기술연구원 세라믹공정센터, 136-791 서울시 성북구 하월곡동 39-1
²연세대학교 공과대학 화학공학과, 120-749 서울시 서대문구 신촌동 134

Yong-Ho Kim , Jong Sung Lim^†, Youn-Woo Lee , Jong-Ku Park¹, and Chang Ha Lee²

Supercritical Fluid Research Lab., Korea Institute of Science & Technology, 39-1 Hawolgok-dong, Sungbuk-gu, Seoul 136-791, Korea
¹Ceramic Processing Center, Korea Institute of Science & Technology, 39-1 Hawolgok-dong, Sungbuk-gu, Seoul 136-791, Korea
²Department of Chemical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul 120-749, Korea

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초록

초임계상태에서 공용매의 첨가는 용매의 밀도와 성질을 변화시켜 용해력을 증진시키게 된다. 이러한 이유로 초임계 유체를 이용한 추출공정에서 추출효율을 높이기 위해 공용매를 첨가하는 방법을 많이 사용한다. 본 연구에서는 급속분말사출성형공정 중 초임계 CO2를 이용한 탈지 공정에서 공용매 첨가가 탈지시간에 미치는 영향을 고찰하였다. 공용매로는 methanol, 1-butanol, n-hexane, dichloromethane을 사용하였다. Paraffin wax가 주결합제인 시편의 경우 348.15 K, 25 MPa의 조건에서 5 wt%, n-hexane을 첨가하면 순수 초임계 CO2만을 이용하여 탈지할 때보다 탈지속도가 2배 이상 증가하였고, 압력과 공용매의 농도 증가에 따라 탈지시간을 더욱 단축시킬 수 있었다. 또한 탈지속도를 Fick의 diffusion model에 적용시켜 계산한 결과 실험값과 잘 일치하는 것을 확인하였고, 이를 이용하여 paraffin wax의 확산도를 구할 수 있었다.

In this study, we have investigated the effect of cosolvents on supercritical CO2 debinding in metal injection molding(MIM) process. We used methanol, 1-butanol, n-hexane, and dichloromethane as cosolvents. In paraffin wax based system, the debinding rate was enhanced when non-polar or midium-polar cosolvents such as n-hexane or dichloromethane was added into supercritical CO2, while it was decreased when polar cosolvents such as methanol or 1-butanol was added. For example, the debinding rate was enhanced more than two times by adding 5wt% of n-hexane into supercritical CO2 under 348.2 K, 25 MPa in paraffin wax based system. It was also found that the debinding rate was much more enhanced with increasing concentration of n-hexane or dichloromethane in paraffin wax based system and increasing system pressure. The kinetics of debinding were investigated using the Fick’s diffusion model and they showed good agreement with experimental data. By using this model, the diffusivities of paraffin wax into supercritical solvent could be evaluated in each experimental conditions.

Keywords:Supercritical Debinding;Cosolvents;Metal Injection Molding;Supercritical CO2

[References]

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Summers EM, Akinc M, J. Am. Ceram. Soc., 83(7), 1670 (2000)
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Wei TS, German RM, "Two-Stage Fast Debinding of Injection Molding Powder Compacts," U.S. Patent, 5,028,367 (1991)
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Park JK, Bull. Korean Chem. Soc., 12, 27 (1997)
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Rei M, Milke EC, Gomes RM, Schaeffer L, Souza JP, Mater. Lett., 52, 360 (2002)
Kim YH, Lim JS, Lee YW, Kim SN, Park JK, J. KPMI, 8(2), 91 (2001)
Dobbs JM, Wong JM, Lahiere RJ, Johnston KP, Ind. Eng. Chem. Res., 26, 56 (1987)
Dobbs JM, Wong JM, Johnston KP, J. Chem. Eng. Data, 31, 303 (1986)
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Koo BS, Seo JT, Bae HK, HWAHAK KONGHAK, 31(2), 229 (1993)
Hildebrand JH, Scott RL, The Solubility of Non-Electrolytes, 3rd ed., Dover, New York (1949)
Blanks RF, Prausnitz JM, Ind. Eng. Chem. Fundam., 3(1), 1 (1964)
Hansen CM, J. Paint Tech., 39(505), 104 (1967)
Hansen CM, J. Paint Tech., 39(511), 505 (1967)
Chen SA, J. Appl. Polym. Sci., 15, 1247 (1971)
Lee JO, Polym.(Korea), 12(1), 1 (1988)
Crank J, The Mathematics of Diffusion, 2nd ed., Oxford University Press, Oxford (1977)
Shewmon PG, Diffusion in Solids, McGraw-Hill, U.S. (1963)
Kaufman JJ, Stratton AW, "Encyclopedia of Polymer Science and Engineering," John Wiley & Sons (1989)
Fedors RF, Polym. Eng. Sci., 14(2), 147 (1974)
Takishima S, Matsumoto H, Nagasaki H, Masuoka H, Mukai Y, Sakai T, Kag. Kog. Ronbunshu, 17(4), 716 (1991)
Joseph ML, Storozynsky E, Ashraf-Khorassani M, Supercritical Fluid Technology-Theoretical and Applied Approaches to Analytical Chemistry, Bright, F.V., McNally, M.E.P., Eds.; ACS Symposium Series 488; American Chemical Society; Washington, D.C., 336 (1992)

[Related Articles]

[1] Shivashankar TS, German RM, J. Am. Ceram. Soc., 82(5), 1146 (1999)

[2] Summers EM, Akinc M, J. Am. Ceram. Soc., 83(7), 1670 (2000)

[3] Johnson KP, "Process for Fabricating Parts from Particulate Material," U.S. Patent, No. 4,765,950 (1988)

[4] Wiech RE, "Method for Removing Binder from a Green Body," U.S. Patent, No. 4,404,166 (1983)

[5] Wei TS, German RM, "Two-Stage Fast Debinding of Injection Molding Powder Compacts," U.S. Patent, 5,028,367 (1991)

[6] Krueger DC, "Process for Improving the Debinding Rate of Ceramic and Metal Injection Molded Products," U.S. Patent, No. 5,531,958 (1996)

[7] Park JK, Bull. Korean Chem. Soc., 12, 27 (1997)

[8] Shimizu T, Mochizuki S, Mechanical Eng. Laboratory, 51(2), 41 (1997)

[9] Chartier T, Ferrato M, Baumard JB, J. Eur. Ceram. Soc., 15, 899 (1995)

[10] Rei M, Milke EC, Gomes RM, Schaeffer L, Souza JP, Mater. Lett., 52, 360 (2002)

[11] Kim YH, Lim JS, Lee YW, Kim SN, Park JK, J. KPMI, 8(2), 91 (2001)

[12] Dobbs JM, Wong JM, Lahiere RJ, Johnston KP, Ind. Eng. Chem. Res., 26, 56 (1987)

[13] Dobbs JM, Wong JM, Johnston KP, J. Chem. Eng. Data, 31, 303 (1986)

[14] Nishikawa E, Wakao N, Nakashima N, J. Supercrit. Fluids, 4(4), 265 (1991)

[15] Foster NR, Singh H, Yun J, Tomasko DL, Macnaughton SJ, Ind. Eng. Chem. Res., 32, 2849 (1993)

[16] Koo BS, Seo JT, Bae HK, HWAHAK KONGHAK, 31(2), 229 (1993)

[17] Hildebrand JH, Scott RL, The Solubility of Non-Electrolytes, 3rd ed., Dover, New York (1949)

[18] Blanks RF, Prausnitz JM, Ind. Eng. Chem. Fundam., 3(1), 1 (1964)

[19] Hansen CM, J. Paint Tech., 39(505), 104 (1967)

[20] Hansen CM, J. Paint Tech., 39(511), 505 (1967)

[21] Chen SA, J. Appl. Polym. Sci., 15, 1247 (1971)

[22] Lee JO, Polym.(Korea), 12(1), 1 (1988)

[23] Crank J, The Mathematics of Diffusion, 2nd ed., Oxford University Press, Oxford (1977)

[24] Shewmon PG, Diffusion in Solids, McGraw-Hill, U.S. (1963)

[25] Kaufman JJ, Stratton AW, "Encyclopedia of Polymer Science and Engineering," John Wiley & Sons (1989)

[26] Fedors RF, Polym. Eng. Sci., 14(2), 147 (1974)

[27] Takishima S, Matsumoto H, Nagasaki H, Masuoka H, Mukai Y, Sakai T, Kag. Kog. Ronbunshu, 17(4), 716 (1991)

[28] Joseph ML, Storozynsky E, Ashraf-Khorassani M, Supercritical Fluid Technology-Theoretical and Applied Approaches to Analytical Chemistry, Bright, F.V., McNally, M.E.P., Eds.; ACS Symposium Series 488; American Chemical Society; Washington, D.C., 336 (1992)