The first generation of high performance composite materials made from completely biodegradable natural fibre reinforced plastics has been produced by a UK-based consortium. These fabric-based materials are believed to be the first of their kind, using long, aligned natural fibres to reinforce naturally derived plastics.
This work is being undertaken as part of COMBINE, a UK based collaborative project co-funded by the Technology Strategy Board, whose objectives are to develop high performance bio-derived composites for structural applications. Half way through the two and a half year project, the first generation of materials has now been developed and plans are underway to manufacture three industrial demonstrator parts. End-user partners within the consortium, Fairline Boats and Lightweight Medical, have begun to develop a marine component and a section of a mobile incubator respectively. An opportunity has recently arisen for a UK based moulding company or end-user to join the project and to assist with the development of the case study parts.
Natural fibres are already being used to reinforce conventional plastics, for example in injection moulded or press moulded interior parts for the automotive industry. However, the natural fibres are generally short and randomly oriented so their use is limited due to the relatively low mechanical properties obtained. Plastics made from renewable resources are even further from market when it comes to their use in engineering products.
The COMBINE project is converting the natural fibres into long, aligned reinforcements to exploit the inherent mechanical properties of plants in structural applications with the added advantage of having a lower weight than conventional reinforcements such as glass fibres.
Polylactic acid (PLA), a bio plastic made from corn, has been identified as a suitable matrix material by the consortium, whilst polypropylene is also being considered as a partial nearer-to-market solution. These are then combined with the natural fibre reinforcements of choice, flax and hemp fibre, both easily grown in the UK. Novel spinning and weaving techniques are being developed to optimise material properties. Further work will include process optimisation, painting, bonding and moulding.
In addition to Fairline Boats and Lightweight Medical, the consortium consists of seven other UK partners - Queen Mary University of London, Springdale Natural Products, E&F Composites, John L Brierley, Sam Weller and Sons, NetComposites (Project Coordinator) and Tilsatec.
Dr Brendon Weager, Project Manager at NetComposites, said ”The development and use of renewable materials is becoming increasingly important in today’s environmentally conscious society. This project is making great strides towards harnessing the true potential of natural fibres and biopolymers to make high-performance biomaterials a reality.”