Effect of Cooling Parameters on In-Mold Flow Behavior in the Microinjection Molding of Piezoelectric Pumps

Abstract

In this study, the analysis of piezoelectric pumps produced by microinjection was conducted in a computational setting. Using the Face-Centered Cubic (FCC) design of experiments approach, this analysis examined in detail how cooling water temperature and Reynolds number impact product quality and production performance. With cooling water inlet temperatures between 20°C and 30°C and Reynolds numbers from 8000 to 12000, several critical quality parameters were analyzed, including fill time, injection pressure, wall shear stress, sink mark depth, volumetric shrinkage and residual deformation. The results showed that maintaining injection pressure between 113.8 and 116.1 MPa supported effective mold filling, while wall shear stress values between 0.2566 and 0.2617 MPa preserved mold longevity and enhanced surface quality. Volumetric shrinkage held at 2.775% improved dimensional accuracy and product stability, and controlling sink mark depth between 0.2995 and 0.2999 mm minimized surface deformation. Additionally, an optimized fill time of 0.3327 seconds ensured consistent temperature distribution during filling, enhancing overall fill quality. These findings illustrate that by optimizing cooling parameters and flow control, high-quality, dimensionally accurate piezoelectric pumps can be manufactured via microinjection. This study provides a comprehensive methodology to improve both production efficiency and product quality. Furthermore, the presented data will serve as a valuable guide for researchers in the production of piezoelectric pumps using the microinjection molding method.

Keywords

• Cooling
• Microinjection Molding
• Piezoelectric Pump
• Warpage

References

1. [1] V. Piotter, W. Bauer, T. Benzler, A. Emde. Injection molding of components for microsystems. Microsystem Technologies. 2001; 7: 99-102.
2. [2] Fu H, Xu H, Liu Y, Yang Z, Kormakov S, Wu D, Sun J. Overview of injection molding technology for processing polymers and their composites. ES Materials & Manufacturing.2020; 8(20): 3-23. https://doi.org/10.30919/esmm5f713
3. [3] Dekel Z, Kenig S. Micro-injection molding of polymer nanocomposites composition-process-properties relationship. International Polymer Processing. 2021; 36(3): 276-286. https://doi.org/10.1515/ipp-2020-4065
4. [4] Bellantone V, Surace R, Fassi I. Quality definition in micro injection molding process by means of surface characterization parameters. Polymers. 2022; 14(18): 3775. https://doi.org/10.3390/polym14183775
5. [5] Speranza V, Liparoti S, Pantani R, Titimanlio G. Prediction of morphology development within micro–injection molding samples. Polymer. 2021; 228:123850. https://doi.org/10.1016/j.polymer.2021.123850
6. [6] Gal CW, Han JS, Park JM, Kim JH, Park SJ. Fabrication of micro piezoelectric rod array using metallic mold system for mass production. The International Journal of Advanced Manufacturing Technology. 2019;101:2815–2823. https://doi.org/10.1007/s00170-018-2986-6
7. [7] Tuckerman D, Pease R. High-performance heat sinking for VLSI. IEEE Electron Device Letters. 1981;2(5):126–129. https://doi.ogr/ 10.1109/EDL.1981.25367
8. [8] Manz A, Harrison DJ, Verpoorte EMJ, Fettinger JC, Paulus A, Lüdi H, Widmer HM Planar chips technology for miniaturization and integration of separation techniques into monitoring systems—capillary electrophoresis on a chip. J. Chromatography A. 1992;593 (1-2):253–258. https://doi.org/10.1016/0021-9673(92)80293-4

9. [9] Kulkarni H, Zohaib K, Khusru A, Aiyappa KS. Application of piezoelectric technology in automotive systems. Materials Today: Proceedings. 2018; 5(10): 21299-21304. https://doi.org/10.1016/j.matpr.2018.06.532
10. [10] Chang HT, Wen CY, Lee CY. Design, analysis and optimization of an electromagnetic actuator for a micro impedance pump. Journal Of Micromech. Microeng. 2009;19(8):85026. https://doi.org/10.1088/0960-1317/19/8/085026
11. [11] Li X, Lİ D, Liu X, Chang H. Ultra-monodisperse droplet formation using PMMA microchannels integrated with low-pulsation electrolysis micropumps. Sensors and Actuators B. 2016;229:466–475. https://doi.org/10.1016/j.snb.2016.01.122
12. [12] Chang HT, Lee CY, Wen CY. Design and modeling of electromagnetic actuator in mems-based valveless impedance pump. Microsystem Technologies. 2007;13:1615–1622. https://doi.org/10.1007/s00542-006-0332-7
13. [13] Yeo HG, Jung J, Sim M, Jang JE, Choi H. Integrated piezoelectric AIN thin film with SU-8/PDMS supporting layer for flexible sensor array. Sensors.2020;20(1):315. https://doi.org/10.3390/s20010315
14. [14] Karaağaç İ, Uluer O, Gürün H, Mert F. Plastik Enjeksiyon Kalıplarında Maliyet Tahmini. In 1st International Symposium on Plastic and Rubber Technologies and Exhibition. 2013; 29-40.
15. [15] Schulze R, Heinrich M, Nossol P, Forke R, Sborikas M, Tsapkolenko A, Billep D, Wegener M, Kroll L, Gessner, T. Piezoelectric P (VDF-TrFE) transducers assembled with micro injection molded polymers. Sensors and Actuators A: Physical. 2014;208:159-165. https://doi.org/10.1016/j.sna.2013.12.032
16. [16] Wegener M, Künstler W, Richter K, Gerhard-Multhaupt R. Ferroelectric polarization in stretched piezo- and pyroelectric poly (vinylidene fluoride-hexafluoropropylene) copolymer films.Journal of Applied Physics. 2002; 92 (12):7442-7447. https://doi.org/10.1063/1.1524313
17. [17] Arlt K, Wegener M. Piezoelectric PZT / PVDF-copolymer 0-3 composites; Aspects on film preparation and electrical poling. IEEE Transactions on Dielectrics Electrical Insulation. 2010;17(4):1178-1184. https://doi.org/10.1109/TDEI.2010.5539688
18. [18] Wegener M, Bauer S. Microstorms in cellular polymers: A route to soft piezoelectric transducer materials with engineered macroscopic dipoles. Chem. Phys. Chem.2005;66: 1014-1025. https://doi.org/10.1002/cphc.200400517
19. [19] Chen WL, Huang CY, Hung CW, Optimization of plastic injection molding process by dual response surface method with non-linear programming. International Journal for Computer-Aided Engineering and Software. 2009;27(8):951-996.
20. [20] Lee HK, Huang JC, Yang GE, Kim HG. Analysis of residual stress in thin wall injection molding. Key Engineering Materials. 2006;306:1331-1336. https://doi.org/10.4028/www.scientific.net/KEM.306-308.1331
21. [21] Zheng G, Guo W, Wang Q, Guo X. Influence of processing parameters on warpage according to the Taguchi experiment. Journal of Mechanical Science and Technology. 2015; 29(10):4153-4158. https://doi.org/10.1007/s12206-015-0909-0
22. [22] Tosello G, Costa FS. High precision validation of micro injection molding process simulations. Journal of Manufacturing Processes. 2019;48: 236-248. https://doi.org/10.1016/j.jmapro.2019.10.014
23. [23] Wu HL, Wang YH. Using taguchi method to optimize Molding Process Parameters of Chair Base. Applied Mechanics and Materials. 2013; 271:1190-1194. https://doi.org/10.4028/www.scientific.net/AMM.271-272.1190
24. [24] Bharti PK, Khan MI. Recent methods for optimization of plastic injection molding process-A retrospective and literature review. International Journal of Engineering Science and Technology. 2010;2(9):4540-4554.
25. [25] Fu JY. The viscosity model of Ti-6Al-4V feedstocks in metal powder injection molding. Applied Mechanics and Materials. 2013;.275: 2161-2165. https://doi.org/10.4028/www.scientific.net/AMM.275-277.2161
26. [26] Qian YP, Wang Y, Huang JH, Zhou XZ. Study on the optimization of conformal cooling channels for plastic injection mold. Advanced Materials Research. 2012; 591: 502-506. https://doi.org/10.4028/www.scientific.net/AMR.591-593.502
27. [27] Huang ZM, Kim HM, Youn JR, Song YS. Injection molding of carbon fiber composite automotive wheel. Fibers and Polymers. 2019; 20: 2665-2671. https://doi.org/10.1007/s12221-019-9636-y
28. [28] Wang G, Wang Y, Yang D. Study on automotive back door panel injection molding process simulation and process parameter optimization. Advances in Materials Science and Engineering. 2021;(1): 9996423. https://doi.org/10.1155/2021/9996423
29. [29] Yang H, Jo H, Lee H, Park, H, Park J. A New Approach to Optimization of the Injection Molding on Automotive Interior Parts. SAE Technical Paper.2016; 1:3-6. https://doi.org/10.4271/2016-01-0306
30. [30] Spina R. Injection moulding of automotive components: comparison between hot runner systems for a case study. Journal of Materials Processing Technology. 2004; 155 :1497-1504. https://doi.org/10.1016/j.jmatprotec.2004.04.359
31. [31] Park HS, Dang XP. Development of a smart plastic injection mold with conformal cooling channels. Procedia Manufacturing. 2017;10: 48-59. https://doi.org/10.1016/j.promfg.2017.07.020
32. [32] Jauernick M, Schütz C, Sterz J, Horn B. Composite Engine Block–Challenges for Design and Material. Technologies for economical and functional lightweight design. 2019; 51-60. https://doi.org/10.1007/978-3-662-58206-0_5