Recycling of composite materials

An economic survey of composite manufacturing was carried out to help to identify suitable fibre/resin systems for recycling trials. Three separate recycling strategies were also adopted. The first of these was the re-use of in-process polyester/glass prepreg offcuts, which were quantified and then reprocessed using a simple pressing technique. Three different panel types were pressed and subjected to comparative physical and mechanical testing. Solvent recycling trials were carried out on carbon fibre/PEEK APC-2 Initially methylene chloride proved successful, so concentrated sulphuric acid was used. Polymer recovered using the acid was checked for purity against 380-P moulding compound. The final process investigated was recovery of aramid fibre (Twaron(TM)) from an epoxy matrix by solvent swelling, the solvent system used being 50% DMSO and 50% Toluene at 105 degrees C. The recovered fibre was tested against virgin fibre to ascertain what degradation of the properties resulted from the process.