Determining the minimum, critical and maximum fibre content for twisted yarn reinforced plant fibre composites

Abstract The effect of fibre volume fraction on the physical and tensile properties of aligned plant fibre composites (PFCs) produced via vacuum infusion has been investigated. There is no clear correlation between fibre volume fraction and porosity. However, low fibre content PFCs are prone to intra-yarn voids, while high fibre content PFCs are prone to inter-yarn voids. This is due to changing resin flow dynamics with increasing fibre content. The tensile behaviour of PFCs with increasing fibre content is similar to that of conventional fibre reinforced plastics (FRPs). Interestingly, the non-linear stress–strain response of plant fibres has been transferred to the composites. Fibre content and tensile properties are found to be linearly related, as per the rule of mixtures. A void content of up to 4% is found to have minimal effect on the tensile properties of PFCs. The minimum and critical ( v f , crit ) fibre volume fractions for aligned flax and jute–polyester composites are found to be substantially higher than conventional aligned FRPs; v f , crit for jute–polyester and carbon–polyester is 8.1% and 2.4%, respectively. A simple model has also been developed to approximate the theoretical maximum obtainable fibre volume fraction of PFCs reinforced with staple fibre yarns. The absolute theoretical maximum fibre content is found to be 58.9%, which agrees with experimental values in literature. A high v f , crit (∼10%) and low v f , max (∼45%) implies that the range of useful fibre volume fractions for PFCs containing staple fibre twisted yarns is only 35%.

[1]  Mike Clifford,et al.  Modelling the effect of yarn twist on the tensile strength of unidirectional plant fibre yarn composites , 2013 .

[2]  F. Göktepe,et al.  Packing Density of Compact Yarns , 2007 .

[3]  P. Wambua,et al.  Natural fibres: can they replace glass in fibre reinforced plastics? , 2001 .

[4]  M. Lewin.  Handbook of Fiber Chemistry , 2006 .

[5]  C. Baley.  Analysis of the flax fibres tensile behaviour and analysis of the tensile stiffness increase , 2002 .

[6]  J. Baets,et al.  Determination of the optimal flax fibre preparation for use in UD flax-epoxy composites , 2011 .

[7]  M. Clifford,et al.  Hydroxyethylcellulose surface treatment of natural fibres: the new ‘twist’ in yarn preparation and optimization for composites applicability , 2012, Journal of Materials Science.

[8]  Bo Madsen,et al.  Hemp yarn reinforced composites – II. Tensile properties , 2007 .

[9]  A. Reiterer,et al.  Experimental evidence for a mechanical function of the cellulose microfibril angle in wood cell walls , 1999 .

[10]  M. Ansell,et al.  Jute-reinforced polyester composites , 1985 .

[11]  Lu Zhang,et al.  Commingled natural fibre/polypropylene wrap spun yarns for structured thermoplastic composites , 2010 .

[12]  T. Peijs,et al.  The effect of fibre volume fraction and mercerization on the properties of all-cellulose composites , 2008 .

[13]  K. Pickering.  Properties and performance of natural-fibre composites , 2008 .

[14]  Ning Pan,et al.  Development of a Constitutive Theory for Short Fiber Yams Part III: Effects of Fiber Orientation and Bending Deformation , 1993 .

[15]  B. Madsen,et al.  Plant fibre composites – porosity and stiffness , 2009 .

[16]  B. Harris.  Engineering composite materials , 1986 .

[17]  B. Madsen,et al.  Hemp yarn reinforced composites - I: Yarn characteristics , 2007 .

[18]  M. Reboredo,et al.  Influence of fiber volume fraction and aspect ratio in resol–sisal composites , 2003 .

[19]  R. A. Tait,et al.  Fracture mechanism of plant fibres , 1980 .

[20]  P. Herrera-Franco,et al.  Mechanical properties of continuous natural fibre-reinforced polymer composites , 2004 .

[21]  H. L. Cox.  The elasticity and strength of paper and other fibrous materials , 1952 .

[22]  B. Madsen,et al.  Plant fibre composites - porosity and volumetric interaction , 2007 .

[23]  Alexei Vazquez,et al.  Structure–Properties Relationship of Short Jute Fiber-reinforced Polypropylene Composites , 2005 .

[24]  M.J.A. van den Oever,et al.  Thermoplastic composites based on flax fibres and polypropylene: Influence of fibre length and fibre volume fraction on mechanical properties , 1998 .

[25]  N. Pan.  Theoretical determination of the optimal fiber volume fraction and fiber‐matrix property compatibility of short fiber composites , 1993 .

[26]  C. Santulli,et al.  Influence of microstructural voids on the mechanical and impact properties in commingled E-glass/polypropylene thermoplastic composites , 2002 .

[27]  K. Satyanarayana,et al.  An empirical evaluation of structure-property relationships in natural fibres and their fracture behaviour , 1986 .

[28]  C. Pavithran,et al.  Impact properties of natural fibre composites , 1987 .

[29]  T. Peijs,et al.  The Optimisation of Flax Fibre Yarns for the Development of High-Performance Natural Fibre Composites: , 2003 .