Defect Optimization in Injection Molded Parts Using Metal Epoxy Composite (MEC) as a Hybrid Mold by Taguchi Method

Nazirul Ikhwan Bin Ismail; Radhwan Bin Hussin; Suhaimi Bin Illias

doi:10.58915/aset.v5i2.3528

Authors

Nazirul Ikhwan Bin Ismail Universiti Malaysia Perlis
Radhwan Bin Hussin Universiti Malaysia Perlis
Suhaimi Bin Illias Universiti Malaysia Perlis

DOI:

https://doi.org/10.58915/aset.v5i2.3528

Keywords:

Autodesk Moldflow Insight, Injection Molding, Metal Epoxy Composite (MEC), Shrinkage, Taguchi Method, Warpage

Abstract

Injection molding with alternative mold materials, such as metal epoxy composite (MEC), offers potential cost reductions and manufacturing flexibility; however, their lower thermal conductivity increases susceptibility to dimensional defects. This study aims to optimize injection molding process parameters to minimize warpage and shrinkage defects in molded parts produced using MEC as a hybrid mold insert. A simulation-based approach was adopted using Autodesk Moldflow, integrated with the Taguchi method for systematic process optimization. Six key process parameters were selected and arranged using an orthogonal array, while signal-to-noise ratio analysis and analysis of variance were applied to identify statistically significant factors. The results indicate that warpage is predominantly influenced by packing pressure and mold temperature, whereas shrinkage is mainly governed by melt temperature. Confirmation tests demonstrated strong agreement between predicted and simulated results, with error margins of 1.12% for warpage and 0.44% for shrinkage, confirming the reliability of the optimization model. Overall, the findings demonstrate that MEC hybrid molds can achieve acceptable dimensional stability when supported by appropriate parameter optimization, thereby providing a cost-effective alternative for small to medium-scale injection molding applications.

References

[1] Rosato, D. V., Rosato, M. G., Rosato, D. V. Injection molding handbook. Springer (2004).

https://doi.org/10.1016/B978-185617431-2/50007-4

[2] Osswald, T. A., Turng, L. S. Injection molding handbook (2nd ed.). Hanser Publishers (2008).

[3] Beaumont, J. P., Runner, R., Brown, A. Successful injection molding. Hanser Publishers (2009).

[4] Strong, A. B. Plastics materials and processing (3rd ed.). Pearson Education (2006).

[5] Menges, G., Mohren, P., Michaeli, W. How to make injection molds. Hanser Publishers (2001). https://doi.org/10.3139/9783446401808.fm

[6] Rees, H. Mold engineering. Hanser Publishers (2002).

[7] Ma, J., Shang, T., Ren, L., Zhang, H. Thermal conductivity enhancement of epoxy composites with metal fillers. Composites Science and Technology, vol 67, issue 13 (2007).

[8] Hussin, R., Sharif, S., Abd Rahim, E., Zainal Abidin, M. A., Mohd Khushairi, M. T. Development of metal epoxy composite mold inserts for rapid tooling applications. Journal of Manufacturing Processes, vol 64 (2021). https://doi.org/10.1108/RPJ-01-2020-0025

[9] Mohd Khushairi, M. T., Sharif, S., Mohd Ani, F. C. Optimization of injection molding parameters using the Taguchi method. Journal of Advanced Manufacturing Technology, vol 9, issue 2 (2015) pp.25-36.

[10] Hussin, R., Sharif, S., Nabiałek, M., Abd Rahim, E., Zainal Abidin, M. A. Thermal and mechanical characterization of metal epoxy composite molds. Materials Today: Proceedings, vol 42 (2021).

[11] Abdullah, M. F., Sharif, S., Mohd Khushairi, M. T. Effect of thermal properties on dimensional stability of epoxy based molds. Applied Mechanics and Materials, vol 833 (2016).

[12] Chen, S. C., Chang, J. A., Hsu, C. H. Warpage analysis of injection molded parts considering mold material effects. Polymer Engineering and Science, vol 56, issue 6 (2016).

[13] Rahman, M. A., Azmi, A. I., Idris, M. I. Process parameter optimization in hybrid mold injection molding. International Journal of Advanced Manufacturing Technology, vol 113 (2021).

[14] Zhu, Y., Zhang, Y., Wang, F. Application of the Taguchi method in the optimization of injection molding process parameters. Journal of Materials Processing Technology, vol 152, issue 1 (2004) pp.1-6.

[15] Qian, L., Zhang, H., Tang, Y. Thermal performance improvement of epoxy molds for rapid tooling applications. Polymer Testing, vol 105 (2022).

[16] Taguchi, G. Introduction to quality engineering. Asian Productivity Organization (1990).

[17] Montgomery, D. C. Design and analysis of experiments (8th ed.). John Wiley & Sons (2013).

[18] Zhang, Y., Wang, H., Liu, X. Simulation based optimization of injection molding defects. Polymer Engineering and Science, vol 60, issue 9 (2020).

[19] Hussin, R., Sharif, S., Abd Rahim, E. Simulation driven optimization of injection molding parameters for hybrid molds. Journal of Manufacturing Systems, vol 63 (2022).

[20] Zhou, J., Li, D., Chen, X. Effects of packing pressure on warpage behavior of injection molded parts. International Polymer Processing, vol 33, issue 4 (2018).

[21] Wang, G., Huang, H., Li, Z. Shrinkage control in injection molded thermoplastics. Materials & Design, vol 181 (2019).