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Rapid cooling of injection mold for high-curvature parts using CO2 cooling module  

Se-Ho Lee (Dep. of Aeronautical & Mechanical Design Eng., Korea Nat'l Univ. of Transportation)
Ho-Sang Lee (Dep. of Aeronautical & Mechanical Design Eng., Korea Nat'l Univ. of Transportation)
Publication Information
Design & Manufacturing / v.16, no.4, 2022 , pp. 67-74 More about this Journal
Abstract
Injection molding is a cyclic process comprising of cooling phase as the largest part of this cycle. Providing efficient cooling in lesser cycle times is of significant importance in the molding industry. Recently, lots of researches have been done for rapid cooling of a hot-spot area using CO2 in injection molding. The CO2 flows under high pressure through small, flexible capillary tubes to the point of use, where it expands to create a snow and gas mixture at a temperature of -79℃. The gaseous CO2 removes heat from the mold and releases it into the atmosphere. In this paper, a CO2 cooling module was applied to an injection mold in order to cool a large area cavity uniformly and quickly, and the cooling performance of the injection mold was investigated. The product was a high-curvature molded part with a molding area of 300x100mm. Heat cartridges were installed in a stationary mold, and CO2 cooling module was inserted inside a movable mold. Through structural analysis, it was confirmed that the maximum deformation of mold with CO2 cooling module was 0.09mm. A CO2 feed system with a heat exchanger was used for cooling experiments. The CO2 was injected into the holes on both sides of the supply pipe of the cooling module and discharged through hexagon blocks to cool the mold. It took 5.8 seconds to cool the mold from an average temperature of 140℃ to 70℃. Through the experiment using CO2 cooling module, it was found that a cooling rate of up to 12.98℃/s and an average of 10.18℃/s could be achieved.
Keywords
Cooling Module; Carbon Dioxide; Mold Cooling; Structural Analysis; Cooling Rate;
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Times Cited By KSCI : 1  (Citation Analysis)
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1 Meckley, J. and Edwards, R., "A study on the design and effectiveness of conformal cooling channels in rapid tooling inserts", The Technology Interface Journal, Vol. 10, No.1, 2009. 
2 Altaf, K., Raghavan, V. R. and Rani, A. M. A., "Comparative thermal analysis of circular and profiled cooling channels for injection mold tools", Journal of Applied Sciences, Vol.11, pp. 2068-2071, 2011.    DOI
3 Park, S., and Kwon, T., "Optimal cooling system design for the injection molding process", Polym. Eng. Sci., Vol.38, pp. 1450-1462, 1998.    DOI
4 Sachs, E., Wylonis, E., Allen, S., Cima, M., and Guo, H., "Production of injection molding tooling with conformal cooling channels using the three dimensional printing process", Polym. Eng. Sci., Vol.40, pp. 1232-1247, 2000.    DOI
5 Shayfull, Z., Sharif, S., Zain, A. M., Ghazali, M., and Saad, R. M., "Potential of conformal cooling channels in rapid heat cycle molding: A review", Adv. Polym. Tech., Vol.33, Paper No. 21381, 2014. 
6 Kim, W. S., Hong, M. P., Park, J. S., Lee, Y. S., Cha, K. J., Sung, J. H., Jung, M. H., and Lee, Y. H., "Case studies on applications of conformal cooling channel based on DMT technology", J. Kor. Soc. Manuf. Process Eng., Vol.14, pp. 9-14, 2015. 
7 Kim, C.-H., Oh, S. A., and Park, K., "Investigation of the functional characteristics of injection molds with conformal cooling channels", Trans. Korean Soc. Mech. Eng. A, Vol.44, pp. 681-688, 2020.    DOI
8 Saifullah, A.B.M and Masood, S. H., "Cycle time reduction in injection molding with conformal cooling channels", Proceedings of the International Conference on Mechanical Engineering, Dhaka, Bangladesh, pp. 29-31, 2007. 
9 Oh, S.-H., Ha, J.-W., and Park, K., "Adaptive conformal cooling of injection mold using additively manufactured TPMS structures", Polymer, Vol.14, pp. 181-194, 2022.    DOI
10 Mayatal, B.-Z. and Shavit, A., "On the integral Joule-Thomson effect", Cryogenics, Vol.34, pp. 19-23, 1994.    DOI
11 Matin, N. S. and Haghighi, B., "Calculation of the Joule-Thomson inversion curves from cubic equation of state", Fluid Phase Equilibrium, Vol.175, pp. 273-284, 2000.    DOI
12 Seidl, M., Bobek, J., Safka, J., Habr, J., Novakova, I., and Behalek, L., "Utilizing of inner porous structure in injection moulds for application of special cooling method", Journal of Physics: Conference Series 709 012203, pp. 1-5, 2016. 
13 Linde North America, "Liquid CO2 spot cooling gets into tight spots in molds", Plastics Technology, pp. 11, 2013. 
14 Kim, M. J. and Choi, J. H., "Study on the rapid cooling method of an injection mold using the Joule-Thomson effect", J. of Korean Soc. Manuf. Tech. Eng., Vol. 3, pp. 306-311, 2022. 
15 Bae, H. S., Park, D. H., and Lee, H. S., "Design of cooling module with CO2 for rapid cooling of injection mold", J. Korean Soc. Precis. Eng., Vol. 39, pp. 477-484, 2022.   DOI
16 Bae, H. S., Park, D. H., and Lee, H. S., "Experimental study on hot-plate cooling with CO2 gas", Trans. Korean Soc. Mech. Eng. A, Vol.45, pp. 489-495, 2021.    DOI