Research Papers

Influence of Injection and Cavity Pressure on the Demoulding Force in Micro-Injection Moulding

[+] Author and Article Information
C. A. Griffiths

School of Mechanical, Aerospace
and Civil Engineering,
The University of Manchester,
Manchester M13 9PL, UK

S. S. Dimov

School of Mechanical Engineering,
The University of Birmingham,
Birmingham B15 2TT, UK

S. G. Scholz

Institute for Applied Computer Science,
Karlsruhe Institute of Technology,
Karlsruhe 76344, Germany

G. Tosello

Department of Mechanical Engineering,
Technical University of Denmark,
2800 Kgs. Lyngby, Denmark

A. Rees

College of Engineering,
Swansea University,
Swansea SA2 8PP, UK

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING. Manuscript received May 13, 2011; final manuscript received February 26, 2014; published online April 11, 2014. Assoc. Editor: Allen Y. Yi.

J. Manuf. Sci. Eng 136(3), 031014 (Apr 11, 2014) (10 pages) Paper No: MANU-11-1170; doi: 10.1115/1.4026983 History: Received May 13, 2011; Revised February 26, 2014

The paper reports an experimental study that investigates part demoulding behavior in micro-injection moulding with a focus on the effects of pressure and temperature on the demoulding forces. In particular, the demoulding performance of a representative microfluidics part was studied as a function of four process parameters, melt temperature, mould temperature, holding pressure, and injection speed, employing the design of experiment approach. In addition, the results obtained using different combinations of process parameters were analyzed to identify the best processing conditions in regards to demoulding behavior of microparts when utilizing a COC polymer to mould them.

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Mani, M. R., Surace, R., Ferreira, P., Segal, J., Fassi, I., and Ratchev, S., 2013, “Process Parameter Effects on Dimensional Accuracy of Micro-Injection Moulded Part,” ASME J. Micro Nano-Manuf., 1(3), p. 031003. [CrossRef]
Whitesides, G. M., 2006, “The Origins and the Future of Microfluidics. Lab on Chip,” Nature, 422(7101), pp. 368–373. [CrossRef]
Trotta, G., Bellantone, V., Surace, R., and Fassi, I., 2012, “Effects of Process Parameters on the Properties of Replicated Polymeric Parts,” ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, pp. 169–176.
Yao, D., and Kim, B., 2004, “Scaling Issues in Miniaturization of Injection Molded Parts,” ASME J. Manuf. Sci. Eng., 126(4), pp. 733–739. [CrossRef]
Arnaud, B., Sébastien, J., Paul, B., and Philippe, R., 2003, “Microstereolithography: A Review,” Proceedings of the Material Research Society Symposium, Rapid Prototyping Technologies, Vol. 758, pp. 3–15.
Melchels, F. P. W., Feijen, J., and Grijpma, D. W., 2010, “A Review on Stereolithography and Its Applications in Biomedical Engineering,” Biomaterials, 31(24), pp. 6121–6130. [CrossRef] [PubMed]
Regenfuss, P., Streek, A., Hartwig, L., Klötzer, S., Brabant, Th., Horn, M., Ebert, R., and Exner, H., 2007, “Principles of Laser Micro Sintering,” Rapid Prototyping J., 13(4), pp. 204–212. [CrossRef]
Said, A. A., Dugan, M., Bado, P., Bellouard, Y., Scott, A., and Mabesa, J. R., Jr., 2004, “Manufacturing by Laser Direct-Write of Three-Dimensional Devices Containing Optical and Microfluidic Networks,” Proc. SPIE, 5339, pp. 194–204. [CrossRef]
Attia, U. M., Marson, S., and Alcock, J. R., “Micro-Injection Moulding of Polymer Microfluidic Devices,” Microfluid. Nanofluid., 7(1), pp. 1–28. [CrossRef]
Haberstroh, E., and Brandt, M., 2002, “Determination of Mechanical Properties of Thermoplastics Suitable for Micro Systems,” Macromol. Mater. Eng., 287(12), pp. 881–888. [CrossRef]
Navabpour, P., Teer, D. G., Hitt, D. J., and Gilbert, M., 2006, “Evaluation of Non-Stick Properties of Magnetron-Sputtered Coatings for Moulds Used for the Processing of Polymers,” Surf. Coatings Technol., 201(6), pp. 3802–3809. [CrossRef]
Menges, G., 1993, “How to Make Injection Molds,” G.Menges and P.Mohren, eds., Hanser Publisher, Munich, Vienna, New York.
Heyderman, L. J., Schift, H., David, C., Gobrecht, J., and Schweizer, T., 2000, “Flow Behaviour of Thin Polymer Films Used for Hot Embossing Lithography,” Microelectron. Eng., 54(3-4), pp. 229–245. [CrossRef]
Kwak, S., Kim, T., Park, S., and Lee, K., 2003, “Layout and Sizing of Ejector Pins for Injection Mould Design Using the Wavelet Transform,” Proc. Inst. Mech. Eng., Part B, 217(4), pp. 463–473. [CrossRef]
Gui, D. Y., Ernst, L. J., Jansen, K. M. B., Yang, D. G., Goumans, L., Bressers, H. J. L., Janssen, J. H. J., 2008, “Effects of Molding Pressure on the Warpage and the Viscoelasticities of HVQFN Packages,” J. Appl. Polym. Sci., 109(3), pp. 2016–2022. [CrossRef]
An, C.-C., and Chen, R.-H., 2007, “Experimental Study of Demolding Properties on Stereolithography Tooling,” ASME J. Manuf. Sci. Eng., 129(4), pp. 843–848. [CrossRef]
Fu, G., Tor, S. B., Loh, N. H., Tay, B. Y., and Hardt, D. E., 2008, “The Demolding of Powder Injection Molded Micro-Structures: Analysis, Simulation and Experiment,” J. Micromech. Microeng., 18(7), p. 075024. [CrossRef]
Sha, B., Dimov, S., Griffiths, C., and Packianather, M. S., 2007, “Micro-Injection Moulding: Factors Affecting the Achievable Aspect Ratios,” Int. J. Adv. Manuf. Technol., 33(1), pp. 147–156. [CrossRef]
Griffiths, C. A., Dimov, S. S., Brousseau, E. B., and Packianather, M. S., 2008, “The Finite Element Analysis of Melt Flow Behaviour in Micro-Injection Moulding,” Proc. Inst. Mech. Eng., Part B, 222(9), pp. 1107–1118. [CrossRef]
Griffiths, C. A., Dimov, S. S., and Brousseau, E. B., 2008, “Microinjection Moulding: The Influence of Runner Systems on Flow Behaviour and Melt Fill of Multiple Microcavities,” Proc. Inst. Mech. Eng., Part B, 222(9), pp. 1119–1130. [CrossRef]
Pontes, A. J., and Pouzada, A. S., 2004, “Ejection Force in Tubular Injection Moldings. Part I: Effect of Processing Conditions,” Polym. Eng. Sci., 44(5), pp. 891–897. [CrossRef]
Hopkinson, N., and Dickens, P. M., 1999, “Study of Ejection Forces in the AIM Process,” Mater. Des., 20(2-3), pp. 99–105. [CrossRef]
Pontes, A. J., Pouzada, A. S., Pantani, R., and Titomanlio, G., 2005, “Ejection Force of Tubular Injection Moldings. Part II: A Prediction Model,” Polym. Eng. Sci., 45(3), pp. 325–332. [CrossRef]
Charmeau, J.-Y., Chailly, M., Gilbert, V., and Béreaux, Y., 2008, “Influence of Mould Surface Coatings in Injection Moulding. Application to the Ejection Stage,” Int. J. Mater. Form., 1(1), pp. 699–702. [CrossRef]
Griffiths, C. A., Dimov, S. S., Brousseau, E. B., Chouquet, C., Gavillet, J., and Bigot, S., 2009, “Investigation of Surface Treatment Effects in Micro-Injection-Moulding,” Int. J. Adv. Manuf. Technol., 47(1–4), pp. 99–110. [CrossRef]
Griffiths, C. A., Dimov, S. S., Scholz, S., and Tosello, G., 2011, “Cavity Air Flow Behavior During Filling in Microinjection Moulding,” ASME J. Manuf. Sci. Eng., 133(1), p. 011006. [CrossRef]
Kazmer, D., and Barkan, P., 1997, “The Process Capability of Multi-Cavity Pressure Control for the Injection Molding Process,” Polym. Eng. Sci., 37(11), pp. 1880–1895. [CrossRef]
Gao, F., Patterson, W. I., and Kamal, M. R., 1996, “Cavity Pressure Control During the Cooling Stage in Thermoplastic Injection Molding,” Polym. Eng. Sci., 36(19), pp. 2467–2476. [CrossRef]
Orzechowski, S., Paris, A., and Dobin, C. J. B., 1998, “A Process Monitoring and Control System for Injection Molding Using Nozzle-Based Pressure and Temperature Sensors,” Proceedings of the 1998 56th ANTEC, pp. 424–428.
Kazmer, D., and Barkan.P., 1997, “Multi-Cavity Pressure Control in the Filling and Packing Stages of the Injection Molding Process,” Polym. Eng. Sci., 37(11), pp. 1865–1879. [CrossRef]
Zhao, J., Mayes, R. H., Chen, G. E., Xie, H., and Chan, P. S., 2003, “Effects of Process Parameters on the Micro Molding Process,” Polym. Eng. Sci., 43(9), pp. 1542–1554. [CrossRef]
Su, Y.-C., Shah, J., and Lin, L., 2004, “Implementation and Analysis of Polymeric Microstructure Replication by Micro Injection Molding,” J. Micromech. Microeng., 14(3), pp. 415–422. [CrossRef]
Kurt, M., Kamber, O., Kaynak, Y., Atakok.G., and Girit, O., 2009, “Experimental Investigation of Plastic Injection Molding: Assessment of the Effects of Cavity Pressure and Mold Temperature on the Quality of the Final Products,” Mater. Des., 30(8), pp. 3217–3224. [CrossRef]
Tsai, K. M., Hsieh, C. Y., and Lo, W. C., 2009, “A Study of the Effects of Process Parameters for Injection Molding on Surface Quality of Optical Lenses,” J. Mater. Process. Technol., 209(7), pp. 3469–3477. [CrossRef]
Huang, M. S., 2007, “Cavity Pressure Based Grey Prediction of the Filling-to-Packing Switchover Point for Injection Molding,” J. Mater. Process. Technol., 183(2-3), pp. 419–424. [CrossRef]
Collins, C., 1999, “Monitoring Cavity Pressure Perfects Injection Molding,” Assembly Autom., 19(3), pp. 197–202. [CrossRef]
Park, J. H., Yang, K. M., and Kang, K. S., 2005, “A Quality Function Deployment Methodology With Signal and Noise Ratio for Improvement of Wassermann's Weights,” Int. J. Adv. Manuf. Technol., 26, pp. 631–637. [CrossRef]
Montgomery, D. C., 2004, Design and Analysis of Experiments, 6th ed., Wiley, New York, pp. 1–450.


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Fig. 1

PC part demoulding defect

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Fig. 2

μ-IM injection and cavity pressure curves, including characteristic numbers

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Fig. 3

Curve of demoulding force over time

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Fig. 4

(a) Microfluidic part (b) mould insert

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Fig. 5

Microchannel features

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Fig. 6

Cavity (Pc) and injection (Pi) measurement positions

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Fig. 7

Normal distribution of P results

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Fig. 8

Histogram of Pwork and Femax experimental results (the plotted points represent the average values of the 10 trails at each setting while the error bars represent the 1σ standard deviation)

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Fig. 9

Histogram of Pmax and Femax experimental results (the plotted points represent the average values of the 10 trails at each setting while the error bars represent the 1σ standard deviation)

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Fig. 10

Main effects' plot of Femax (error bars represent the average 1σ standard deviation of the considered effects; Femax σ ranges from 0.6 to 1.4 N)

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Fig. 11

Main effects' plot of Pmax (error bars represent the average 1σ)

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Fig. 12

Main effects' plot of Pwork (error bars represent the average 1σ)

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Fig. 13

The effects of Vi, Ph, and Tm interactions on Pmax



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