Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter February 20, 2017

The Influence of Different Melt Temperatures on the Mechanical Properties of Injection Molded PA-12 and the Post Process Detection by Thermal Analysis

T. Meyer, A. Harland, B. Haworth, C. Holmes, T. Lucas and P. Sherratt

Abstract

Polyamide 12 (PA-12) test plates were injection molded using different melt temperatures and the influence on mechanical properties was investigated using quasi-static tensile and instrumented impact behavior in two conditioned states: dried, and following accelerated moisture intake. Energy absorption in tension is strongly dependent on process temperature (variations up to 99%) and additional variation (around 18%) was evident when testing at different conditioning states. Under high-velocity loading, the total impact energy varied by up to 8.70% and 9.05%, when systematic changes were made to process melt temperature and at moisture content, respectively, with all samples failing ductile. Differential Scanning Calorimetry (DSC) was used to characterise the unique endothermic melting behavior of molded PA-12 samples, by linking different process histories to the respective mechanical properties. With focus on the first heating curve progression, significant changes within the endothermic melting region were pointed out and quantified by using MatLab (software), proving DSC as a reliable testing tool for post-production analysis with increased practical implications regarding quality control as well as failure analysis. Findings for the initial heating curve progression were explained by studying the re-crystallisation peak values during cooling phase and obtained data for the second heating.


*Correspondence address, Mail address: Tino Meyer, Sport Technology Institute, Loughborough University, Loughborough, UK, Leicestershire, LE11 3TU TEST, E-mail:

References

Aharoni, S. M.: Properties of 12-Nylon, N Nylons: Their Synthesis, Strucutre and Properties, Wiley, New York (1997)Search in Google Scholar

Alema, C., Casanovas, J., “Computer Experiments on Crystalline Nylons: Structural Analysis of Nylons with Large Aliphatic Segments”, Colloid Polym. Sci., 282, 535543 (2004) 10.1007/s00396-003-0957-3Search in Google Scholar

Apichartpattanasiri, S., Hay, J. N. and Kukureka, S. N., “A Study of the Tribological Behaviour of Polyamide 66 with Varying Injection-Moulding Parameters”, Wear, 251, 15571566 (2001) 10.1016/S0043-1648(01)00794-3Search in Google Scholar

Athreya, S. R., Kalaitzidou, K. and Das, S., “Mechanical and Microstructural Properties of Nylon-12/Carbon Black Composites: Selective Laser Sintering versus Melt Compounding and Injection Molding.Compos. Sci. Technol., 71, 506510 (2011) 10.1016/j.compscitech.2010.12.028Search in Google Scholar

Carriěre, F. J., Sekiguchi, H., “Thermal Properties of Amino Acid Type PolyamidesChem. Zvesti, 30, 281291 (1976)Search in Google Scholar

Corté, L., Beaume, F. and Leibler, L., “Crystalline Organization and Toughening: Example of Polyamide-12”, Polymer, 46, 27482757 (2005) 10.1016/j.polymer.2005.01.040Search in Google Scholar

Ghijsels, A., Waals, F., “Differetial Scanning Calorimetry: A Powerful Tool for the Characterization of Thermoplastics”, Polym. Test., 1, 149160 (1980) 10.1016/0142-9418(80)90038-0Search in Google Scholar

Hinrichsen, G., “The Role of Water in Polyamides”, Colloid Polym. Sci., 14, 914 (1978) 10.1007/BF01746685Search in Google Scholar

Hiramatsu, N., Hashida, S. and Hirakaw, S., “Formation of α Form Nylon 12 under High Pressure”, Japn. J. Appl. Phys., Part 1, 21, 651654 (1982) 10.1143/JJAP.21.651Search in Google Scholar

Van Hooreweder, B., Moens, D., Boonen, R., Kruth, J. and Sas, P., “On the Difference in Material Structure and Fatigue Properties of Nylon Specimens Produced by Injection Molding and Selective Laser Sintering”, Polym. Test., 32, 972981 (2013) 10.1016/j.polymertesting.2013.04.014Search in Google Scholar

Ishikawa, T., Nagai, S., “Formation of A-Nylon 12 by Solution Casting”, J. Polym. Sci., 15, 13151317 (1977) 10.1002/pol.1977.180150716Search in Google Scholar

Ishikawa, T., Nagai, S. and Municipal, O., “Thermal Behavior of a Nylon-12”, J. Polym. Sci., 18, 14131419 (1980)Search in Google Scholar

Jia, N., Fraenkel, H. A. and Kagan, V. A., “Effects of Moisture Conditioning Methods on Mechanical Properties of Injection Molded Nylon 6”, J. Reinf. Plast. Compos., 23, 729737 (2004) 10.1177/0731684404030730Search in Google Scholar

Jia, N., Kagan, V. A., “Mechanical Performance of Polyamides with Influence of Moisture and Temperature – Accurate Evaluation and Better Understanding” in Plastics Failure Analysis and Prevention, Moalli, J. (Ed.), Elsevier, Amsterdam, p. 95104 (2001)10.1016/B978-188420792-1.50014-7Search in Google Scholar

Khanna, Y. P., Kuhn, W. P., “Measurement of Crystalline Index in Nylons by DSC: Complexities and Recommendations”, J. Polym. Sci., Part B: Polym. Phys., 35, 22192231 (1997) 10.1002/(SICI)1099-0488(199710)35:14<2219::AID-POLB3>3.0.CO;2-RSearch in Google Scholar

Klein, N., Selivansky, D. and Marom, G., “The Effects of a Nucleating Agent and of Fibers on the Crystallization of Nylon 66 Matrices”, Polym. Compos., 16, 189197 (1995) 10.1002/pc.750160302Search in Google Scholar

Kohan, M. I.: Nylon Plastics, Wiley, New York (1973)Search in Google Scholar

Kusić, D., Slabe, J. M., Svečko, R. and Grum, J., “The Impact of Process Parameters on Test Specimen Deviations and their Correlation with AE Signals Captured during the Injection Moulding Cycle”, Polym. Test., 32, 583593 (2013) 10.1016/j.polymertesting.2013.02.006Search in Google Scholar

Lafranche, E., Krawczak, P., “Injection Moulding of Long Glass Fiber Reinforced Polyamide 66: Processing Conditions/Microstructure/Flexural Properties Relationship”, Adv. Polym. Technol., 24, 114131 (2005) 10.1002/adv.20035Search in Google Scholar

Lal, S. K., Vasudevan, H., “Optimization of Injection Moulding Process Parameters in the Moulding of Low Density Polyethylene (LDPE)”, International Journal of Engineering Research and Development, 7, 3539 (2013)Search in Google Scholar

Li, L., Koch, M. H. J. and De Jeu, W.H., “Crystalline Structure and Morphology in Nylon-12: A Small- and Wide-Angle X-Ray Scattering Study”, Macromolecules, 36, 16261632 (2003) 10.1021/ma025732lSearch in Google Scholar

Li, Y., Zhang, G. and Yan, D., “Synthesis and Crystallization Behavior of Nylon 12, 14. I. Preparation and Melting Behavior”, J. Appl. Polym. Sci., 88, 15811589 (2003) 10.1002/app.11826Search in Google Scholar

Mathias, L. J., Johnson, C. G., “Solid-State NMR Investigation of Nylon 12”, Macromolecules, 24, 61146122 (1991) 10.1021/ma00023a011Search in Google Scholar

Mehat, N. M., Kamaruddin, S. and Othman, A. R., “Investigating the Effects of Injection Moulding Process Parameters on Multiple Tensile Characteristics of Plastic Spur Gear via Experimental Approach”, Adv. Mater. Res., 748, 544548 (2013) 10.4028/www.scientific.net/amr.748.544Search in Google Scholar

Mirvar, S. E., Kaleybar, R. M. and Afsari, A., “Optimization of Injection Molding Process Parameters to Increase the Tensile Strength in Polyamide-Specimen Using the Taguchi Method”, Adv. Mater. Res., 341–342, 395399 (2011)10.4028/www.scientific.net/AMR.341-342.395Search in Google Scholar

Murthy, N. S., “Hydrogen Bonding, Mobility, and Structural Transitions in Aliphatic Polyamides”, J. Polym Sci., Part B: Polym. Phys., 44, 17631782 (2006) 10.1002/polb.20833Search in Google Scholar

Murthy, N. S., Kagan, V. A. and Bray, R.G., “Effect of Melt Temperature and Skin-Core Morphology on the Mechanical Performance of Nylon 6”, Polym. Eng. Sci., 42, 940950 (2002) 10.1002/pen.11003Search in Google Scholar

Phang, I. Y., Liu, T., Mohamed, A., Pramoda, K. P., Chen, L., Chow, S. Y., He, C., Lu, X. and Hu, X., “Morphology, Thermal and Mechanical Properties of Nylon 12/Organoclay Nanocomposites Prepared by Melt Compounding”, Polym. Int., 464, 456464 (2005) 10.1002/pi.1721Search in Google Scholar

Plasticseurope, “Plastics – the Facts 2014 An Analysis of European Plastics Production, Demand and Waste Data”, Plasticseuorpe, Brussels (2014)Search in Google Scholar

Puffr, R., Kubanek, V.: Lactam-Based Polyamides, 1st Volume, CRC Press, Boca Raton (1991)10.1201/9780367813062-1Search in Google Scholar

Schmiederer, D., Schmachtenberg, E., “Einfluesse auf die Eigenschaften kleiner und Duennwandiger Spritzgussteile”, Zeitschrift Kunststofftechnik/Journal of Plastics Technology, 2, 121 (2006)Search in Google Scholar

Seguela, R., “Critical Review of the Molecular Topology of Semicrystalline Polymers: The Origin and Assessment of Intercrystalline Tie Molecules and Chain Entanglements”, J. Polym. Sci., Part B: Polym. Phys., 43, 17291748 (2005) 10.1002/polb.20414Search in Google Scholar

Stamhuis, J. E., Pennings, A. J., “Crystallization of Polyamides under Elevated Pressure: 6. Pressure-Induced Crystallization from the Melt and Annealing of Folded-Chain Crystals of Nylon-12, Polylaurolactam under Pressure”, Polymer, 18, 667674 (1977) 10.1016/0032-3861(77)90233-6Search in Google Scholar

Zarringhalam, H., Hopkinson, N., Kamperman, N. F. and de Vlieger, J. J., “Effects of Processing on Microstructure and Properties of SLS Nylon 12”, Mater. Sci. Eng., 436, 172180 (2006) 10.1016/j.msea.2006.07.084Search in Google Scholar

Zarringhalam, H., Majewski, C. and Hopkinson, N., “Degree of Particle Melt in Nylon-12 Selective Laser-Sintered Parts”, Rapid Prototyping Journal, 15, 126132 (2009) 10.1108/13552540910943423Search in Google Scholar

Zhou, Y., Mallick, P. K., “Effects of Melt Temperature and Hold Pressure on the Tensile and Fatigue Properties of an Injection Molded Talc-Filled Polypropylene”, Polym. Eng. Sci., 45, 755763 (2005) 10.1002/pen.20301Search in Google Scholar

Received: 2016-04-05
Accepted: 2016-06-28
Published Online: 2017-02-20
Published in Print: 2017-03-03

© 2017, Carl Hanser Verlag, Munich