Abstract
In this study, a thermoforming process for manufacturing micro-structured polystyrene (PS) films is investigated to characterize the effects of significant processing parameters. The present micro-thermoforming process utilizes a mold core with five concave rectangular grooves (each of width 0.4-1.2 mm and a depth of 1 mm). Two types of PS films (thicknesses of 50 and 190 μm) are employed to examine the effect of film thickness. Three main processing parameters namely heating temperature, heating time, and mold core temperature are analyzed. The results show that as the width of the groove in the mold core decreases, the forming ratio (depth-to-width ratio of the thermoformed micro-feature) slightly reduces, consequently indicating poor thermoforming. Both thin and thick PS films exhibit similar forming results under favorable conditions. However, when the processing conditions are not suitably applied, the thick film shows the worst result. From the design of experiment analysis using a normalized forming ratio, the mold core temperature is found to be the most influential factor in the thermoforming process of manufacturing micro-structured PS films.
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This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B4012100).
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This paper was presented at ICMDT 2019, Shiroyama Hotel, Kagoshima, Japan, April 24–27, 2019. Recommended by Guest Editor Haedo Jeong.
Bong-Kee Lee is an Associate Professor in School of Mechanical Engineering at Chonnam National University. He earned his Ph.|D. ^degree in 2009 from Pohang University of Science and Technology (POSTECH). His research interests lie in precision micro/nano molding technologies and manufacturing of multi-scale functional plastic systems.
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Nguyen, T.K., Lee, BK. Investigation of processing parameters in micro-thermoforming of micro-structured polystyrene film. J Mech Sci Technol 33, 5669–5675 (2019). https://doi.org/10.1007/s12206-019-1109-0
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DOI: https://doi.org/10.1007/s12206-019-1109-0