Browse > Article
http://dx.doi.org/10.5228/KSTP.2013.22.1.48

The Effect of Various Molding Methods for Precision Optical Products Using Birefringence Analysis  

Min, I.K. (Dankook University Graduate School)
Cho, S.W. (LG Display)
Yoon, K.H. (Dankook University Graduate School)
Publication Information
Transactions of Materials Processing / v.22, no.1, 2013 , pp. 48-53 More about this Journal
Abstract
As the adoption of injection molding technology increases, injected-molded optical products require higher dimensional accuracy and optical stability than ever before. In the present study, four kinds of molding methods, i.e., conventional injection molding (CIM), injection/compression molding (ICM), rapid heat and cooling the mold(RHCM) and rapid injection/compression molding (RICM) were selected in order to investigate the optical anisotropy of a 7 inch Light Guide Plate(LGP) by examining the gap-wise distribution of birefringence and the extinction angle. The results indicate that the compression process can decrease flow-induced birefringence over the whole region and that rapid heating can decrease the birefringence level better than conventional molding. In addition, for the combination of compression and rapid heating a reversal flow was detected from the distribution of the extinction angle near the gate.
Keywords
Injection/Compression Molding; Rapid Heating and Cooling the Mold(RHCM); Rapid-Injection/Compression Molding(RICM); Birefringence; Indicatrix;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 T. H. Lin, 2009, Ph. D, Thesis, University of Akron, Ohio.
2 Y. B. Lee, T. H. Kwon, K. H. Yoon, 2002, Numerical Prediction of Residual Stresses and Birefringence in Injection/Compression Molded Center-Gated Disk. Part II, Polym. Eng. Sci, Vol. 42, No. 11, pp. 2273-2292.   DOI   ScienceOn
3 S. Matsuda, A. Ito, M. Katsuaki, M. Yoshinobu, T. Tooru, 1984, Heat Cycle Injection Compression Molding Method, US. Patent 4442061.
4 M. C. Jeng, S. C. Chen, P. S. Minh, J. A. Chang, C. S. Chung, 2010, Rapid Mold Temperature Control in Injection Molding by using Steam Heating, Int. Commun. Heat Mass Transfer, Vol. 37, No. 9, pp. 1295-1304.   DOI   ScienceOn
5 E. Hecht, 2002, Optics, 4th ed., Addison-Wesley, Massachusetts. pp. 395-468.
6 I. K. Min, K. H. Yoon, 2011, An Experimental Study on the Effects of Injection-molding Types for the Birefringence Distribution in Polycarbonate Discs, Kr-Au. Rheo. J., Vol. 23, No. 3, pp. 155-162.   DOI