The first generation of high-performance composite materials made from completely biodegradable natural fiber-reinforced plastics has been produced by a U.K. consortium. These fabric-based materials are believed to be the first of their kind, using long, aligned natural fibres to reinforce naturally derived plastics.
The work is being undertaken as part of COMBINE, a U.K.-based collaborative project cofunded by the Technology Strategy Board, whose objectives are to develop high-performance, bio-derived composites for structural applications. Halfway 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 U.K.-based molding company or end-user to join the project and to assist with the development of the case study parts.
Natural fibers are already being used to reinforce conventional plastics, for example in injection molded or press molded interior parts for the automotive industry. However, the natural fibers 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 fibers 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 fibers.
Polylactic acid (PLA), a bioplastic made from corn, has been identified as a suitable matrix material by the consortium; polypropylene is also being considered as a partial nearer-to-market solution. These are then combined with the natural fiber reinforcements of choice, flax and hemp fiber, both easily grown in the U.K. Novel spinning and weaving techniques are being developed to optimize material properties. Further work will include process optimization, painting, bonding and molding.
In addition to Fairline Boats and Lightweight Medical, the consortium consists of seven other U.K. partners: Queen Mary University of London, Springdale Natural Products, E&F Composites, John L Brierley, Sam Weller and Sons, NetComposites (Project Coordinator) and Tilsatec.