Injection molded short natural fiber composites (NFC) are studied in this article. Micromechanical models are employed to investigate effects of fiber length distribution, fiber orientation, and fiber/matrix adhesion on mechanical performance of NFCs.
A parametric study showed that length/diameter ratio strongly affects the composite strength, whereas fiber strength has very little influence on strength of the composites when fiber/matrix adhesion is poor. In order to verify conclusions based on theoretical predictions, modeling results are compared with experimental results of wood powder-, flax-, pulp-, and glass fiber composites.
Recommendations on improvement of strength of NFC through change of the internal structure of the materials are formulated based on results of this investigation.
Defosse, M., Wood Composites Are Expanding Among Sectors, Modern plastics ( 2003), http://www.modplas.com
2.
Karus, M., Ortmann, S. and Vogt, D., Use of natural fibers in composites in the German automotive production 1996 till 2003, Free short version, Nova institute (2004), www.N-FiberBase.net
3.
Oksman, K. (2000). Liquid Composite Molding of Natural Fibres, Natural Agrofibres Based Composites, pp. 203—227, ISBN:85-86463-06-X.
4.
Goutianos, S., Peijs, T., Skrifvars, M. and Eng, T. (2000). Textile Reinforcements Based on Flax Fibres for Structural Composites. Part 1 — The Optimisation of Flax Fibre Yarns for High-performance Natural Fibre Composites. Poster Presentation at the 2nd International Conference on Eco-Composites (London), 1—2 September 2003, p3.04.
5.
Gea, S., Goutianos, S., Peijs, T., Skrifvars, M. and Eng, T. (2003). Textile Reinforcements Based on Flax Fibres for Structural Composites. Part 1 — Mechanical Properties of Fabric Based Laminates. Poster Presentation at the 2nd International Conference on Eco-Composites (London), 1—2 September 2003, p3.04.
6.
Oksman, K. (1997). Improved Properties of Thermoplastic Wood Flour Composites, Doctoral Thesis. 1997:17 ISSN:1402-1544 ISRN: LTU-DT—1997:17—SE.
7.
Arzondo, L.M. , Vazquez, A., Carella, J.M. and Pastor, J.M. (2004). A Low-cost, Low Fibre-breakage, Injection Molding Process for Long Sisal Fibre Reinforced Polypropylene, Polymer Engineering and Science, 44: 9; ProQuest Science Journals p. 1766.
8.
Chtourou, H. , Riedl, B. and Ait. Kadi, A. (1992). Reinforcement of Recycled Polyolefins with Wood Fibres, Journal of Reinforced Plastics & Composites, 11.
9.
Wielage, B., Lampke, Th., Utschick, H. and Soergel, F. (2003). Processing of Natural-fibre Reinforced Polymers and the Resulting Dynamic Mechanical Properties, Journal of Materials Processing Technology, 139: 140—146.
10.
Frisk, H. and Schwendemann, D. , Compounding wood fiber with plastics, Kunststoffe plast Europa4/2004 .
11.
Shing-Chung Wong and Yiu-Wing Mai (1999). Essential Fracture Work of Short Fibre Reinforced Polymer Blends, Polymer Engineering and Science, 39: 2; ProQuest Science Journals, p. 356.
12.
Keungjin Shon, K. and White, J.L. (1999). A Comparative Study of Fibre Breakage in Compounding Glass Fibre-reinforced t, Polymer Engineering and Science, 39: 9; ProQuest Science Journals, p. 1757.
Hashemi, S. (2002). Influence of Temperature on Weldline Strength of Injection Molded Short Glass Fibre Styrenemaleic Anhydride Polymer Composites, Plastics, Rubber andComposites, 31(7).
15.
Schut, J. (2002). Why Long-glass Molders are Compounding In-line , Plastics Technology,48: 4; Pro Quest Science Journals, p. 52.
16.
Schut, J.H. (2003). Long-fibre Thermoplastics Extend their Reach, Plastics Technology,49: 4; ProQuest Science Journals, p. 56.
17.
Fara, S. and Pavan, A. (2004). Fibre Orientation Effects on the Fracture of Short Fibre Polymer Composites: On the Existence of a Critical Fibre Orientation on Varying Internal Material Variables, Journal of MaterialsScience, 39: 3619—3628.
18.
Thomason, J.L. (2002). The Influence of Fibre Length and Concentration on the Properties of Glass Fibre Reinforced Polypropylene: 5. Injection Molded Long and Short Fibre PP, Composites: Part A, 33: 1647.
19.
Miklos, M. and Gregory, R. (2003). Common Mistakes in Long-Fibre Molding, Plastics Technology,49: 1; ProQuest Science Journals, p. 40.
20.
Nyström, B. (1999/2000). Karakterisering av kompositers förbränningsegenskaper, SICOMP TR 01-009, Project report VAMP 18, 1999—2002.
21.
Moe Moe Thwea and Kin Liaob (2003). Durability of Bamboo—Glass Fiber Reinforced Polymer Matrix Hybrid Composites, CompositesScience and Technology , 63: 375—387.
22.
Seldén, R., Nyström, B. and Långström, R. (2004). UV Aging of Poly(propylene)/wood-fiber Composites, PolymerComposites, 25(5): 543—553.
23.
Plastics Europe, Association of Plastics Manufacturers, An analysis of plastics consumption and recovery in Europe, www.plasticseurope.org, Published Summer 2004.
24.
George, J., Sreekala, M.S., and Thomas, S. (2001). A review on interface modification and characterisation of natural fiber reinforced plastic composites. Polymer Engineering and Science,41(9); ProQuest Science Journals, pg. 1471.
25.
Keener, T.J., Stuart, R.K. and Brown, T.K. (2004). Maleated coupling agents for natural fiber composites , Composites: Part A35: 357—362
26.
Tsu-Wei Chou (1992). Microstructural design of fiber composites, Cambridge solid state series, ISBN 0 521 35482 X (169—230)
27.
Charles, L., Tucker III Erwin Liang. (1999). Stiffness predictions for unidirectional short-fiber composites: Review and evaluation, Composites Science and Technology59: 655—671.
28.
Andersons, J. , Joffe, R. and Spãrninš , E. (2005). Stiffness and Strength of Flax Fibre/Polymer Matrix Composites, Submitted to PolymerComposites.
29.
Kelly, A. and Tyson, W.R. (1965). Tensile Properties of Fibre-reinforced Metals: Copper/Tungsten and Copper Molybdenum, J. Mech. Phys. Solids , 13: 329.
30.
Fu, S.-Y. and Lauke, B. (1996). Effects of Fiber Length and Fibre Orientation Distribution on the Tensile Strength of Short-fibre-reinforced Polymers, Compos. Sci. Tech., 56: 1179.
31.
Lauke, B. and Fu, S.-Y. (1999). Strength Anisotropy of Misaligned Short-fibre-reinforced Polymers, Compos. Sci. Tech., 59: 699.
32.
Stora Enso Research department Imatra.
33.
Bledzki, A.K. , Reihmane, S. and Gassan, J. (1996). J. Appl. Pol. Sci., 59: 1329—1336.
34.
Kristiina Oksman, K., Långström, R., Nyström, B. and Joseph, K. (2001). The Influence of Fibre Micro Structure on Mechanical Properties and on Fibre Breakage During the Extrusion Process of Natural Fibre Reinforced Thermoplastic Composites, SICOMP TR 01-016.
35.
Andersons, J., Sparnins, E., Joffe, R. and Wallström, L. (2005). Strength Distribution of Elementary Flax Fibres, CompositesScience and Technology , 65: 693—702.
36.
Sandström, M. (2001). Hur olika typer av träfibrer påverkar de mekaniska egenskaperna i kompositmaterial, SICOMP TR 01-006.
37.
Sandström, M. (2001). Hur olika typer av träfibrer påverkar de mekaniska egenskaperna i kompositmaterial, SICOMP TR 01-006.
38.
Saint Gobain Vetrotex homepage, http://www.vetrotex.com/business_info/gstrand2.html#16
39.
Thomason, J.L. (1999). The Influence of Fibre Properties of the Performance of Glass-fibre-reinforced Polyamide 6,6, Compos. Sci. Technol., 59: 2315—2328.
40.
Akay, M. and Barkley, D. (1991). Fibre Orientation and Mechanical Behaviour in Reinforced Thermoplastic Injection Moldings, J. Mater. Sci. , 26: 2731—2742.
