0
Research Papers

Process Parameter Effects on Dimensional Accuracy of Micro-Injection Moulded Part

[+] Author and Article Information
M. R. Mani, J. Segal, S. Ratchev

Manufacturing Research Division,
Faculty of Engineering,
University of Nottingham,
Nottingham NG7 2RD, UK

R. Surace

ITIA-CNR,
Institute of Industrial Technology and Automation,
National Research Council, Bari 70124, Italy

I. Fassi

ITIA-CNR,
Institute of Industrial Technology and Automation,
National Research Council,
Bari 70124, Italy

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF Micro- AND Nano-Manufacturing. Manuscript received September 12, 2012; final manuscript received July 18, 2013; published online August 12, 2013. Assoc. Editor: Liwei Lin.

J. Micro Nano-Manuf 1(3), 031003 (Aug 12, 2013) (8 pages) Paper No: JMNM-12-1056; doi: 10.1115/1.4025073 History: Received September 12, 2012; Received September 12, 2012; Revised July 18, 2013

Micro-injection moulding is becoming increasingly important among the available processes for production of micro-electromechanical systems (MEMS) and microsystem technologies (MSTs), and higher number of polymer products is being manufactured by this process. Due to the sensitive nature of applications of this process, such as medical and aerospace applications, achieving high quality parts with high dimensional accuracy is crucial. In this work, a design of experiment (DoE) approach is used. The aim is to study the effects of three process parameters which are commonly used for research in this domain, on the dimensional accuracy of microchannels with different sizes; they are injection velocity, injection pressure, and melt temperature. The study focuses on two polymers, polyoxymethylene (POM) and liquid crystal polymer (LCP). Experimental results showed that higher melt temperature and injection pressure resulted in higher dimensional accuracy. Nevertheless, high settings for the three parameters resulted in higher percentage of flash in most cases. In conclusion, the most influential factors were shown to be melt temperature and injection pressure.

FIGURES IN THIS ARTICLE
<>
Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Brochure of the Federal Ministry of Education and Research, 2007, ICT 2020 Research and Innovation Published by Federal Ministry of Education and Research, Bonn, Berlin, Bonn.
NEXUS Market Analysis for MEMS and Microsystems III, 2005–2009, NEXUS, Wehrheim, Germany.
Michaeli, W., Rogalla, A., and Ziegmann, C., 2000, “Processing Technologies for the Injection Moulding of Hybrid Microstructures,” Macromol. Mater. Eng., 279, pp. 42–45. [CrossRef]
Heckele, M., and Schomburg, W., 2004, “Review on Micro Moulding of Thermoplastic Polymers,” J. Micromech. Microeng., 14, pp. 1–14. [CrossRef]
Michaeli, W., and Opfermann, D., 2005, “Micro Assembly Injection Moulding: Potential Application in Medical Science,” W.Menz, and S. S.Dimov. eds. 4M2005: First International Conference On Multi-Material Micro Manufacture: 29 June–1 July 2005, Forschungszentrum Karlsruhe, Karlsruhe, Germany. Elsevier, Amsterdam.
Ratchev, S., Turitto, M. eds., 2008, “Micro, Nanomanufacturing Strategic Research Agenda,” Fraunhofer Institute Manufacturing Engineering and Automation, Stuttgart.
Attia, U., Marson, S., and Alcock, J., 2009, “Micro-Injection Moulding of Polymer Microfluidic Devices,” Microfluid Nanofluid, 7, pp. 1–28. [CrossRef]
Jungmeier, A., Vetter, K., and Ehrenstein, G. W., 2009, “Thermally Low Conductive Moulds for Micro Injection Moulding of Thermoplastics,” Proceedings of the Global Conference on Micro Manufacture, Research Publishing, Singapore, 23–25 September 2009, pp. 91–94. [CrossRef]
Giboz, J., Copponnex, T., and Mele, P., 2007, “Microinjection Molding of Thermoplastic Polymers: A Review,” J. Micromech. Microeng., 17, pp. 96–109. [CrossRef]
Zhao, J., Lu, X., Chen, Y., Chow, L. K., Chen, G., Zhao, W., and Samper, V., 2005, “A New Liquid Crystalline Polymer Based Processing Aid and Its Effects on Micro Molding Process,” J. Mater. Process. Technol., 168, pp. 308–315. [CrossRef]
Shukla, S. R., Lofgren, E. A., and Jabarin, S. A., 2005, “Effects of Injection Molding Processing Parameters on Acetaldehyde Generation and Degradation of Polyethylene Terephtalate,” Polym. Int., 54, pp. 946–955. [CrossRef]
Kalima, V., Pietarinen, J., Siitonen, S., Immonen, J., Suvanto, M., Kuittinen, M., Monkkonen, K., and Pakkanen, T. T., 2007, “Transparent Thermoplastics: Replication of Diffractive Optical Elements Using Micro Injection Molding,” Opt. Mater., 30, pp. 285–291. [CrossRef]
Sammoura, F., Kang, J. J., Heo, Y. M., Jung, T. S., and Lin, L., 2007, “Polymeric Microneedle Fabrication Using a Microinjection Molding Technique,” J. Microsyst. Technol., 13(5), pp. 517–522. [CrossRef]
Sammoura, F., Fuh, Y. K., and Lin, L., 2008, “Micromachined Plastic W-Band Bandpass Filters,” Sens. Actuators A, 147(1), pp. 47–51. [CrossRef]
Chu, J., Kamal, M. R., Derdouri, S., and Hrymak, A., 2010, “Characterization of the Micro Injection Moulding Process,” J. Polym. Eng. Sci., 50(6), pp. 1214–1225. [CrossRef]
Attia, U., and Alcock, J. R., 2010, “Optimising Process Conditions for Multiple Quality Criteria in Micro Injection Moulding,” Int. J. Adv. Manuf. Technol., 50, pp. 533–542. [CrossRef]
Yang, D., Liu, C., Xu, Z., Wang, J. Z., and Wang, L. D., 2011, “Effect of Micro Injection Moulding Process Parameters for Various Micro Channels,” J. Key Eng. Mater., 483, pp. 53–57. [CrossRef]
Kuhn, S., Burr, A., Kubler, M., Deckert, M., and Bleesen, C., 2010, “Study on the Replication Quality of Micro Structures in the Injection Moulding Process With Dynamical Tool Tempering Systems,” J. Microsyst. Technol., 16, pp. 1787–1801. [CrossRef]
Fu, G., Tor, S. B., Hardt, D. E., and Loh, N. H., 2011, “Effects of Processing Parameters on the Micro-Channels Replication in Microfluidic Devices Fabricated by Micro Injection Moulding,” J. Microsyst. Technol., 17, pp. 1791–1798. [CrossRef]
Chen, C. S., Liao, W. H., Chien, R. D., and Lin, S. H., 2010, “Micro Injection Molding of a Micro-fluidic Platform,” Int. Commun. Heat Mass Transfer, 37(9), pp. 1290–1294. [CrossRef]
Zhang, N., Chu, J. S., Byrne, C. J., Browne, D. J., and Gilehrist, M. D., 2012, “Replication of Micro/Nano-Scale Features by Micro Injection Molding With a Bulk Metallic Glass Mold Insert,” J. Micromech. Microeng., 22, p. 065019. [CrossRef]
Trotta, G., Surace, R., Modica, F., Spina, R., and Fassi, I., 2011, “Micro Injection Moulding of Polymeric Components,” Int. Conf. Adv. Mater. Process. Technol., 1315, pp. 1273–1278.
Attia, U., and Alcock, J. R., 2011, “Evaluating and Controlling Process Variability in Micro-Injection Moulding,” Int. J. Adv. Manuf. Technol., 52, pp. 183–194. [CrossRef]
Shames, I. H., 2003, Mechanics of Fluids, 4th ed., McGraw-Hill Higher Education, New York
Utracki, L. A., 1985, “A Method of Computation of the Pressure Effect on Melt Viscosity,” J. Polym. Eng. Sci., 25(11), pp. 655–668. [CrossRef]
Potsch, G., and Michaeli, W., 1995, Injection Moulding: An Introduction, Hanser/Gardner Publishers, Inc., Munchen, Germany.
Sedlacek, T., Zatloukal, M., Filip, P., Boldizar, A., and Saha, P., 2004, “On the Effect of Pressure on the Shear and Elongational Viscosities of Polymer Melts,” J. Polym. Eng. Sci., 44(7), pp. 1328–1337 [CrossRef].
Barus, C., 1893, “Isotherms, Isopiestics and Isometrics Relative to Viscosity,” Am. J. Sci., 45, pp. 87–96. [CrossRef]
Throne, J. L., 1979, Plastic Process Engineering, Marcel Dekker, Inc., New York.
Sha, B., Dimov, S., Griffiths, C., and Pckianather, M. S., 2007, “Investigation of Micro Injection Moulding: Factors Affecting the Replication Quality,” J. Mater. Process. Technol., 183, pp. 284–296. [CrossRef]
Belofsky, H., 1995, Plastic: Product Design and Process Engineering, Hanser, New York.
Osswald, T. A., and Menges, G., 1995, Materials Science of Polymers for Engineers, Hanser/Gardner Publishers, Inc., Cincinnati, p. 94.
Battenfeld Micro Molding, the Innovative Solution for Microprecision Parts, http://www.battenfeld.ru/fileadmin/templates/docs/imm/microsystem_presentation.pdf
Vectra Liquid Crystal Polymer (LCP) Brochure, Ticona, http://www.hipolymers.com.ar/pdfs/vectra/diseno/Vectra%20brochure.pdf

Figures

Grahic Jump Location
Fig. 1

Picture of the mould (a) assembled mould (b) pin inserts

Grahic Jump Location
Fig. 2

Schematics of the channels on the pin

Grahic Jump Location
Fig. 3

Measurement points for small (S) and large (L) dimensions of the channels and flash (F)

Grahic Jump Location
Fig. 4

Samples of pin 1 manufactured in POM

Grahic Jump Location
Fig. 5

SEM images of pin 1A manufactured in (a) LCP (T = 330, V = 300, P = 600) and (b) POM (T = 230, V = 250, P = 700)

Grahic Jump Location
Fig. 6

Dimensional error for pins 1 and 2 LCP

Grahic Jump Location
Fig. 7

Dimensional error for pins 1 and 2 POM

Grahic Jump Location
Fig. 8

Percentage flash for pins 1 and 2 LCP

Grahic Jump Location
Fig. 9

Percentage flash for pins 1 and 2 POM

Grahic Jump Location
Fig. 10

Main effect plot (a) and interaction plot (b) for dimensional error

Grahic Jump Location
Fig. 11

Pareto chart for dimensional error

Grahic Jump Location
Fig. 12

Main effect plot (a) and interaction plot (b) for flash

Grahic Jump Location
Fig. 13

Pareto chart for flash

Grahic Jump Location
Fig. 14

Melt viscosity comparison Vectra LCP versus semicrystalline polymers

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In