Effect of fiber content, size and type on board density and withdrawal strength of fasteners in natural fiber-plastic composites made through dry process

Authors

Abstract

In this study, the effects of fiber content, type and size on board density and withdrawal strength of fasteners (nailed and screwed) in joints made in natural fibers-plastic composites produced through a dry process were investigated. Wood-plastic boards were made at a nominal density of 1 g/cm3 and dimensions of 30×20×1 cm. Polypropylene (PP) as the matrix and poplar wood fiber and rice straw fibers as the reinforcement were used together with 4% (based on weight) maleic anhydride grafted polypropylene (MAPP) as the coupling agent. Three levels of dry poplar and rice straw fibers, namely 45%, 60%, and 75% based on the composition by weight at two particle sizes of 20-40 mesh and 40-60 mesh were mixed with PP. Totally, 12 formulations with 3 replications were considered. The final composites were made by pressing the prepared mats between the hot plates of a compression press by employing combinations of temperature and pressure in three stages. After storing the composites at room temperature for 15 days, the density of the boards and withdrawal strength of fasteners were measured. The results showed that fiber content may significantly influence the density of the samples and the fiber size of 40–60 mesh may lead to a higher density. In addition, it was found that poplar fibers (the type of fiber) results in higher withdrawal strength of fastener in the composites than rice straw fibers. Furthermore, the withdrawal strength of fasteners was reduced as the fiber content was increased. However, this effect is dependent...

Keywords


- British Standard. 2007. Wood-plastics Composites (WPC)– Part 1: Test Methods for Characterisation of
WPC Materials and Products.  
- Chaharmahali, M. Kazemi-Najafi, S. Tajvidi, M. 2006. Effect of blending method on mechanical properties
of wood-plastic composites. Journal of Polymer Sci. & Technology. Vol. 20(4). 7 pp.
- Clemons, C. 2002. Wood–plastic composites in the United States. The Interfacing of two Industries. Journal
of Forest Products. Vol. 52(6). 9 pp.
- Ebrahimi, GH. and Rostampour-Haftkhani, A. 2010. Wood–Plastic Composites (Translated), Tehran
University.
- Faezipour, M. Parsapazhuh, D. Kabudani, A. 2001. Composite material of agricultural resources,
(Translated), Tehran University.
- Falk, R.H. Vos, D.J. Cramer, S.M. English, B.W. 2001. Performance of fasteners in wood flourthermoplastic
composite panels. Journal of Forest Products.Vol. 51(1).5 pp.
 - Garjani, F. and Omidvar, A. 2005. Investigation on making and mechanical properties of recycled PE-wheat
straw composites. Journal of Pajouhesh-Sazandegi. Vol (72). 5 pp.
- Karina, M. Onggo, H. Syampurwadi, A. 2007. Physical and mechanical properties of natural fibers filled
polypropylene composites and its recycle. Journal of Biological Sciences. Vol.7 (2). 4 pp.
- Madhoushi, M. Nadalizadeh, H. Ansell, M.P. 2009. Withdrawal strength of fasteners in rice straw fibre–
thermoplastic composites under dry and wet conditions. Journal of Polymer Testing. Vol. 28 (3) 5 pp.
-Mahlberg, A. 2003. Thermal & mechanical analysis of lingo cellulosic- polypropylene composite. Proceeding
of the Fifth International Conference on Wood Fiber–Plastic Composites. Forest Product Society, Madison. WI. 6778
pp.
- Mashkour, M., 2007. Determination and modification of the influence of density on physical and mechanical
properties of wood-polypropylene composites. M.Sc. Thesis. University of Tehran.
- Migneault, S. Koubaa, A. Erchiqui, F. Chaala, A. Englund, K. Krause, C. Wolcott, M. 2008. Effect of fiber
length on processing and properties of extruded wood-fiber/HDPE composites. Journal of Applied Polymer
Science. Vol. 110 (2). 8 pp. 
- Panathapulakkal, S. Zereshkian, A. Sain, M. 2006. Preparation and characterization of wheat straw fibers for
reinforcing application in injection molded thermoplastic composites. Journal of Bioresource Technology. Vol.
97 (2). 8 pp.
- Shakeri, A. and Omidvar, A. 2005. Investigation on the effect of type, quantity and size of straw particles on
the mechanical properties of crops straw-HDPE composites. Journal of Polymer Science & Technology. Vol. 40.
9 pp.
- Shakeri, A., Omidvar, A. Garjana, F. 2005. Investigation of mechanical properties of HDPE–rice straw
composites. Journal of Agri. Sci. & Nature. Resour. Vol. 13. 11 pp.
-Singleton, A.C.N. Bailline, C.A. Beaumont, P.W.R. Peijs. T. 2003. On the mechanical properties, deformation
and fracture of a natural fiber/recycled. Journal of Polymer Composites. Vol. 34 (6). 8 pp.
 - Stark, N.M. Rowlands, R.E. 2002. Effect of wood fiber characteristics on mechanical properties of
wood/polypropylene composites. Journal of wood and fiber science. Vol. 35(2). 8 pp.
- Tabari, A., 2002. Investigation of preparing possibility of polyester-rice straw fibers composites. M.Sc
Thesis. Gorgan Univ. of Agri. and Nat. Res. 
-Tajvidi, M., 1999. Mixture materials of cellulosic fiber and plastic. M.Sc. Thesis. Tehran University.
-Tajvidi, M. Kazemi-Najafi, S. Moteei, N. 2006. Long-Term Water Uptake Behavior of Natural Fiber-
Polypropylene Composite. Journal of Reinforced Composites Materials, Vol. 99 (5). 5 pp.
- Timber structures test methods pull through resistance of timber fasteners. BS EN 1382-2006.  
- Yao, F. Wu, Q. Lei,Y. Xu, Y. 2008. Rice straw fiber-reinforced high-density polyethylene composite: Effect
of fiber type and loading. Journal of Industrial Crops and Products. Vol.28 (1). 10 pp.
- Youngquist. J.A. 1993. Properties of wood fiber and polymer fiber composites. 1st wood fiber–plastic
composites conference. Forest Products Society. 79–86 pp.