Mechanical and Physical Properties of Natural Fibre Composites Author: Cindi Sorensen Contact: Supervisors: Dr E Sazhina and Dr E Manzanares-TaylorDepartment: Mechanical Engineering Motivation Natural fibres are a renewable resource and highly sustainable. The year 2009 has been officially announced the international year of natural fibres. This helps to raise awareness of the availability of natural fibres and to stimulate demand for them, promoting the efficiency of the natural fibres industry. International Conference on Natural Fibres 2009 December 2009, Institute of Materials, Minerals and Mining, London, UK The attendance of the conference by the author has been sponsored by INTERREG project FLAX of PABS, UoB. This has allowed to get first-hand information on current knowledge and applications of natural fibres. The Conference gave the motivation for the formulation of the research topic with applications for medical and construction industry. Aim and Objectives The aim of the project is to explore mechanical and physical properties of composites reinforced by natural fibres (flax and chaff) The project targets the following objectives: To review and evaluate the properties of natural fibres and their composites, and current industry requirements. To design the procedure for impact testing of the composites To design and manufacture a series of plaster samples reinforced by natural fibres (flax and chaff) for Charpy test. This includes designing a specialised mould for efficient samples’ preparation Perform impact testing on samples with varying fibre content for flax and chaff Perform impact testing on flax samples with varying fibre lengths. To assess the environmental and structural benefits, and potential of the new composites for industry. Time Management An extension to my work was granted, as a result the Gannt Chart has been extended into week 43. Why is the Product Innovative Little research has been carried out on impact resistance Natural fibres are sustainable, renewable, Potential use on blast resistant structures Why testing has been carried out When used in industry a material needs to be reliable and follow established standards. Relevant applications of fibres Construction industry: strengthening of building materials for blast resistance Medical Industry: for plaster castings Food packaging Results Flax Fibres Chaff Above fitted curve is following a parabolic shape. Not a very apparent pattern emerging. Possible link through the best fit straight line. Strong link between data, a pattern is evident. Further testing required before a detailed analysis can be made. Moulds designed and specially manufactured for the specimens 1.5% content by weight of flax fibres 10mm long 1.5% content by weight of chaff TopUndersideSpecimens did not break in the centre Specimens did not break in the centre 3 Specimens can be made at a time Mould can be taken apart completelyAngled break showing cause by crack propagation Larger angles of break, very high Size: 10mm x 10mm x 55mm crack propagation factor Conclusion and Discussion The main novelty of the research is seen in addressing the issue of testing of fibre composites under dynamic loading. The increase in mechanical properties of the flax fibre composites are significantly high with a relatively low standard deviation. There is a real potential for a future for this composite in industry. The chaff composites have a very high standard deviation compared to the average impact energy values for each content value. More research into chaff will need to be carried out before a real potential for this composite in industry can be considered. Acknowledgements : Many thanks to my supervisor Dr. Elena Sazhina. To the staff of Pharmacy and Bio molecular Sciences School, especially Professor S Mikhalovsky and Dr L Mikhalovska. The technical staff of SET, especially Tony Brown. Dr. Maria Diakoumi of Civil Engineering Division of SET. Thanks to Catherine Tame and Peter Mathers for their help in the Soil Mechanics Labs. Recommendations for future research: Higher fibre content in composite. Longer fibres, possibly the full length of the specimen. The decay of fibres within a composite over time. Analyse the microstructure of flax fibres and chaff through optical microscopy to see if there is a link between the intensity of micro fractures and crack propagation. Dissemination of the research: Presentation of findings at the INTERREG FLAX project workshop, 27 May Consultations to the MSc Product Innovation and Development student for the work on his project May – Sept This shall provide a continuity of the research. A poster was presented at an LTN event held in May 2010 in London, Natural Fibre Composites, based on a collection for the recent findings by researchers at UoB.