JEC COMPOSITES MAGAZINE - Issue #55 - February/March 2010 - 32

FEATURE … … “Natural Fibres & Environment” Weaving g / High-performance biocomposites: novel aligned natural fibre reinforcements (flax or hemp) and thermoplastics (PP or PLA) have been developed for rapid moulding of thermoplastic biocomposites - the thermoplastic melts on heating to form the matrix of the composite. Processing & performance The new high-performance natural fibre reinforcements have been evaluated in a range of standard composite processes. The flax fabrics were readily processed by hand lay-up and vacuum infusion, whilst the commingled natural fibre-thermoplastic materials were successfully processed by vacuum consolidation and hot press moulding (Figure 2). For the commingled thermoplastic materials, the optimum fibre content was 40% by volume, the best processing temperature was 190°C and pressures of 1-50bar were suitable. The laminates were subjected to a range of tests including tensile, flexural and impact and typical results are in Table 1. Fig. 3: Prototype flax/PLA parts marine headliner panel from Fairline Boats and two interior automotive parts from Jaguar and Land Rover. Biotex flax/PP fabric was selected by Jaguar and Land Rover due to its combination of good mechanical properties and environmental credentials. Prototype door modules from both Land Rover Defender and Jaguar XF models were manufactured and their performance compared to current production parts. The biocomposite Defender Front Door Module was approximately 60% lighter than the current steel part at the same stiffness, while the Jaguar XF Rear Door Module was 35% lighter than the current glass filled PP component for the same thickness. Detailed component evaluation is underway. Commercialisation Fig. 2: Flax/PLA fabric and pre-consolidated sheets Table 1: Typical properties for the new natural fibre composites Property Density (g/cm3) Tensile modulus (GPa) Tensile strength (MPa) Elongation (%) Charpy impact (kJ/m2) 40 vol% 40 vol% woven flax/PLA woven flax/PP 1.34 13.2 102 1.6 33 1.13 8.1 56 1.5 27 33 vol% woven flax/UP 1.33 7.2 68 2.5 28 Following successful development, the materials have been launched commercially as Biotex, backed up by 130 years of experience in spinning and weaving natural textiles and decades of experience in composite materials, processing and applications. The unique twistless technology used in these materials provides a combination of sustainability, performance and processability not previously seen in composites. For the first time, natural fibre composites can provide high levels of performance and the ease of processing normally associated with glass reinforced materials. There are currently three material options - flax, commingled flax/PP and commingled flax/PLA – and the formats available include yarns, woven fabrics and preconsolidated sheets. The materials are already receiving significant interest from a host of sectors including automotive, construction, marine, sports and consumer goods. More information: www.compositesevolution.com Contact: info@compositesevolution.com Acknowledgements These materials were developed during the Combine project, which was co-funded by the UK Technology Strategy Board's Collaborative Research and Development programme (contract no. TP/5/SUS/6/I/H0284C). The contributions of the project partners NetComposites, Queen Mary University of London, Springdale Natural Products, Tilsatec, John L. Brierley, Sam Weller & Sons, Millfield Composites and Fairline Boats are gratefully acknowledged. Recycling The recyclability of the novel biocomposites has also been studied. Flax/PLA laminates were shredded, regranulated, injection moulded and tensile tested and this cycle was performed 5 times. The strength of the recycled material reduced by 10% with each round of recycling but the modulus was unaffected. Flax/PLA is also biodegradable and compostable in the correct conditions. Case studies A range of prototype components (Figure 3) have been developed from the new high performance biocomposite materials including a jec composites magazine / No55 February - March 2010

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JEC COMPOSITES MAGAZINE - Issue #55 - February/March 2010

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #55 - February/March 2010