Design and Analysis of Shell Runners to Improve Cooling Efficiency in Injection Molding of Subminiature Lens

초소형 렌즈 사출성형시 냉각효율 향상을 위한 박판형 러너의 설계 및 해석

  • Yoon, Seung Tak (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology) ;
  • Park, Keun (Dept. of Mechanical System Design Engineering, Seoul Nat'l Univ. of Science and Technology)
  • 윤승탁 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 박근 (서울과학기술대학교 기계시스템디자인공학과)
  • Received : 2015.06.11
  • Accepted : 2015.08.04
  • Published : 2015.10.01


Subminiature lenses are currently widely used in mobile phone cameras and are usually produced by injection molding. The lens molding process has the unique feature of a runner volume that is much larger than the part volume, and this feature should be considered when determining the mold design and molding conditions. In this study, a shell-type runner was proposed as an alternative to the conventional cylindrical runner used for lens molding. An injection molding simulation was performed by applying the proposed shell runner, and the simulation results were compared with those from the cylindrical runner case. It was found that the shell runner could considerably reduce the runner cooling time with only a slight increase in the injection pressure. The effect of the runner thickness was then investigated numerically in terms of the mold filling and cooling characteristics, from which an optimal runner thickness could be determined.


Supported by : 서울과학기술대학교


  1. Kwak, T. S. Ohmori, H. and Bae, W. B., 2004,"A Study on Searching Method of Molding Condition to Control the Thickness Reduction of Optical Lens in Plastic Injection Molding Process," J. Kor. Soc. Precis. Eng., Vol. 21, No. 2, pp. 27-34.
  2. Ha, T. H., Jo, H. H., Song, J. and Jeon, J., 2014, "Mold Technology for Precision Injection Lens," J. Kor. Soc. Precis. Eng., Vol. 31, No. 7, pp. 561-567.
  3. Pazos, M., Baselga, J. and Bravo, J., 2003, "Limiting Thickness Estimation in Polycarbonate Lenses Injection Using CAE Tools," J. Mater. Process. Technol., Vol. 143-144, pp. 438-441.
  4. Lee, H. S., Jeon, W. T. and Kim, S. W., 2012, "Development of Plastic Lenses for High-Resolution Phone Camera by Injection-Compression Molding," Trans. Korean Soc. Mech. Eng. A, Vol. 37, No. 1, pp. 39-46
  5. Yoshii, M., Kuramoto, H., Kawana, T. and Kato, K., 1996, "The Observation and Origin of Micro Flow Marks in the Precision Injection Molding of Poly-Carbonate," Polym. Eng. Sci., Vol. 36, No. 6, pp. 819-826.
  6. Park, K., 2013, "Investigation of Flow Marks in the Injection Molding of Thin Lenses," Samsung Electro-Mechanics Technical Report.
  7. Park, K. and Joo, W., 2008, "Numerical Evaluation of a Plastic Lens by Coupling Injection Molding Analysis with Optical Simulation," Japan. J. Appl. Phy., Vol. 47, No. 11, pp. 8402-8407.
  8. Tsai, K. M. and Tang, B. H., 2014. "Determination of Injection Molding Process Window Based on form Accuracy of Lens Using Response Surface Methodology," Int. J. Adv. Manuf. Technol., Vol. 75, pp. 947-958.
  9. Gim, J. S., Tae, J. S., Jeon, J. H., Choi, J. H. and Rhee, B. O., 2015, "Detection Method of Filling Imbalance in a Multi-Cavity Mold for Small Lens," Int. J. Precis. Eng. Manuf., Vol. 16, No. 3, pp. 531-535.
  10. Yamanoi, M., Kwark, T.S. and Jung, J. K., 2012, "Application of Birefringence CAE in Mould Design of Optic Lens Injection Molding Process," J. Kor. Soc. Manuf. Process Eng., Vol. 11, No. 11, pp. 1-6.
  11. Kim, J. M. and Lyu, M. Y., 2006, "An Application of CAE in the Optimization of Runner size in Injection Molding," Trans. Mater. Process., Vol. 15, No. 5, pp. 347-353.
  12. Tsai, K. M., 2013, "Runner Design to Improve Quality of Plastic Optical Lens," Int. J. Adv. Manuf. Technol., Vol. 66, pp. 523-536.
  13. Sohn, D. H. and Park, K., 2013, "Investigation of Cooling Performance of Injection Molds Using Pulsed Mold Temperature Control," Trans. Korean Soc. Mech. Eng. B, Vol. 37, No.1, pp. 35-41.

Cited by

  1. Three-Dimensional Thermoforming Analysis of an Inner Case with Three Cavities for Refrigerator vol.40, pp.5, 2016,