Energy efficient fibre composites recycling

Abstract: In this project, an investigation will be performed about how to improve thermal properties of recycled composite material. First, a literature study was performed about the potential techniques to improve the heating efficiency of the composites. Heating  techniques,  fibres  and  possible  fillers  were  investigated.    Secondely, an experimental method was set with the material available.   In the laboratory a precedent  work  was  performed  on  the  thermal  conductivity  of  polyamide  12 reinforced  with  glass  fibres.   The  conductivity  of  polyamide  12  reinforced with carbon fibres is measured using the same experimental method to compare the thermal conductivity. In theory, carbon fibres have a better thermal conductivity than glass fibres, this was confirmed by the experiments performed.  During the recycling of thermoplastic fibre composites the scrap will be grinded.  Therefore, the thermal conductivity of small pieces of carbon fibre composites was measured, the  thermal  conductivity  is  reduced  due  to  the  increase  of  air  fraction  and the shortening of the fibres.  The thermal conductivity of small pieces of glass fibre composite was investigated in the previous work, by mixing the grinded pieces of carbon fibre composite and the small pieces of the glass fibre composite the effect on the thermal conductivity was investigated.  It was noticed that using smaller pieces of grinded material allows to reduce the air fraction between the bigger pieces and increase the thermal conductivity.