Investigation into Failure in Mining Wire Ropes—Effect of Crystallinity

Sheila Devasahayam, Veena Sahajwalla, Michael Sng

Moly-Cop Ropes Mayfield NSW 2304 PO Box 245C, Newcastle, Australia.
School of Materials Science & Engineering, University of New South Wales, Sydney, Australia.

DOI: 10.4236/ojopm.2013.32006                

Abstract

A range of blends of polypropylene-polyethylene are investigated for their mechanical performances. These speciality polymer blends are chemically designed to suit high modulus/high load bearing mining wire rope applications subjected to continued bending and tensile stresses and fluctuating loads and are exposed to extreme weather conditions. In this paper we study the influence of different parameters on the performance of the wire ropes: chemistry of polymer, crystallinity of the polymer matrix, and the morphology. The FTIR and SEM studies revealed that the high fraction of polypropylene in polypropylene-polyethylene matrix lead to early failure as a result of incompatibility and phase segregation and high spherulite sizes of the polymer matrix.

Keywords

Mining Wire Ropes; Crystallinity; Polyolefin Blends; Morphology; FTIR; SEM

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Technical Plastic Extrusions. http://www.bellplastics.co.uk/wire_rope_coatings.html
[2]	B. Cordage, “Technical Properties of Synthetic Fibres,” 2012. http://www.barry.ca/publtion/rt-technical-properties-of-synthetic-fibres-oct-08.pdf
[3]	S. Doroudiani, C. B. Park and M. T. Kortschot, “Effect of the Crystallinity and Morphology on the Microcellular Foam Structure of Semicrystalline Polymers,” Polymer Engineering and Science, Vol. 36, No. 21, 1996, pp. 2645-2662. doi:10.1002/pen.10664
[4]	Y. V. Kissin, “Orientation of Isotactic Polypropylene in Crystalline and Amorphous Phases: IR Methods,” Journal of Polymer Science: Polymer Physics, Vol. 21, No. 10, 1983, pp. 2085-2096. doi:10.1002/pol.1983.180211018
[5]	G. Lamberti, V. Brucato and G. Titomanlio, “Orientation and Crystallinity in Film Casting of Polypropylene,” Journal of Applied Polymer Science, Vol. 84, No. 11, 2002, pp. 1981-1992.
[6]	C. E. Miller, “Use of Near-Infrared Spectroscopy to Determine the Composition of High-Density/Low-Density Polyethylene Blend Films,” Applied Spectroscopy, Vol. 47, No. 2, 1993, pp. 139-253. doi:10.1366/0003702934048370
[7]	W. Camacho and S. Karlsson, “NIR, DSC, and FTIR as Quantitative Methods for Compositional Analysis of Blends of Polymers Obtained from Recycled Mixed Plastic Waste,” Polymer Engineering and Science, Vol. 41, No. 9, 2001, pp. 1626-1635. doi:10.1002/pen.10860
[8]	L. Bohn, “Incompatibility and Phase Formation in Solid Polymer Mixures and Graft and Block Copolymers,” Rubber Chemistry and Technology, Vol. 41, No. 2, 1968, pp. 495-513. doi:10.5254/1.3547187
[9]	J. W. Teh, A. Rudin and J. C. Keung, “A Review of Polyethylene-Polypropylene Blends and Their Compatibilization,” Advances in Polymer Technology, Vol. 13, No. 1, 1994, pp. 1-23. doi:10.1002/adv.1994.060130101
[10]	B. Z. Jiang, D. R. Uhlmann and J. B. Vander Sand, “Rubber-Toughening in Polypropylene,” Journal of Applied Polymer Science, Vol. 30, No. 6, 1985, pp. 2485-2504. doi:10.1002/app.1985.070300617
[11]	D. C. Yang, B. L. Zhang, Y. K. Yang, Z. Fang, G. Sun and Z. L. Feng, “Morphology and Properties of Blends of Polypropylene with Ethylene-Propylene Rubber,” Polymer Engineering and Science, Vol. 24, No. 8, 1984, pp. 612-617. doi:10.1002/pen.760240814
[12]	J. G. M. Van Gisbergen, W. F. L. M. Hoeben and H. E. H. Meijer, “Melt Rheology of Electron-Beam-Irradiated Blends, of Polypropylene and Ethylene-Propylene-Diene Monomer (EPDM) Rubber,” Polymer Engineering and Science, Vol. 31, No. 21, 1991, pp. 1539-1544.
[13]	M. Jiang, “Physical Chemistry in Polymer Alloys,” Sichuan Educational Press, Chengdu, 1988.
[14]	L. Ubonnut, S. Thongyai and P. Praserthdam, “Block Copolymer of Polypropylene and Polyethylene by Way of Diisocyanate,” Technology and Innovation for sustainable Development Conference Faculty of Engineering, KhonKaen University, 25-26 January 2006.
[15]	S. Devasahayam, “Interfacial Toughness in Polymer-Layered Laminar Composites,” Journal of Polymer Science Part B: Polymer Physics, Vol. 42, No. 20, 2004, pp. 3822-3835. doi:10.1002/polb.20250
[16]	S. Devasahayam, “Towards Improving Wet-Adhesion in a Metal Oxide-Polymer Coating System,” Journal of Applied Polymer Science, Vol. 99, No. 6, 2006, pp. 3318-3327. doi:10.1002/app.22759
[17]	S. Devasahayam, “Effect of Moisture-Ingress on Adhesion Energy in a Metal Oxide-Polymer System,” Journal of Applied Polymer Science, Vol. 99, No. 5, 2006, pp. 2052-2061. doi:10.1002/app.22588
[18]	A. J. Lovinger and M. L. Williams, “Tensile Properties and Morphology of Blends of Polyethylene and Polypropylene,” Journal of Applied Polymer Science, Vol. 25, No. 8, 1980, pp. 1703-1713. doi:10.1002/app.1980.070250817
[19]	J. L. Way and J. R. Atkinson, “The Influence of Crystallization Temperature on the Deformation of Polypropylene Spherulites,” Journal of Materials Science, Vol. 7, No. 1, 1972, pp. 1345-1346. doi:10.1007/BF00550703
[20]	J. C. Halpin and J. L. Kardos, “Moduli of Crystalline Polymers Employing Composite Theory,” Journal of Applied Physics, Vol. 43, No. 5, 1972, pp. 2235-2241. doi:10.1063/1.1661482
[21]	P. J. Phillips and J. Patel, “The Influence of Morphology on the Tensile Properties of Polyethylenes,” Polymer Engineering and Science, Vol. 18, No. 12, 1978, pp. 943-950. doi:10.1002/pen.760181207
[22]	F. J. Padden and H. D. Keith, “Crystallization in Thin Films of Isotactic Polypropylene,” Journal of Applied Physics, Vol. 37, No. 11, 1966, pp. 4013-4020. doi:10.1063/1.1707968
[23]	F. J. Padden and H. D. Keith, “Mechanism for Lamellar Branching in Isotactic Polypropylene,” Journal of Applied Physics, Vol. 44, No. 3, 1973, pp. 1217-1223. doi:10.1063/1.1662331
[24]	P. Rachtanapun, S. E. M. Selke and L. M. Matuana, “Effect of the High-Density Polyethylene Melt Index on the Microcellular Foaming of High-Density Polyethylene/Polypropylene Blends,” Journal of Applied Polymer Science, Vol. 93, No. 1, 2004, pp. 364-371. doi:10.1002/app.20428
[25]	J. S. Petronyuk, O. V. Priadilova, V. M. Levin, O. A. Ledneva and A. A. Popov, “Structure and Elastic Properties of Immiscible LDPE-PP Blends: Dependence on Composition,” Proceedings of Materials Research Society on Nanomaterials for Structural Applications, Vol. 740, Boston, 2-6 December 2002.