Studio sull'utilizzo della fibra di carbonio riciclata nella produzione di stampi per tecnologia autoclave

After describing the main recycling techniques for thermoset composite materials, this thesis outlines the complete hand lay-up and autoclave curing process for manufacturing a composite mold which produces a support structure for an automotive bumper. The material used is a mat (non-woven fabric) made of recycled carbon fiber (RCF) obtained through pyrolysis. During the lamination phase, difficulties arose due to the material expansion after vacuum pull, which returned to its original thickness. At the end of the curing cycle, the mold exhibited porosity defects and the metallic inserts were not properly integrated into the material, as the mold had not compressed sufficiently. These issues made it necessary to create a second mold after the first one broke. The 3D scans conducted demonstrated globally acceptable values, albeit lower than those of the conventional woven carbon fiber mold. After curing, the geometric deviations were very small, however, a significant distortion of the mold was observed after the post-curing cycle at a higher temperature. Finally, by means of Differential Scanning Calorimetry (DSC), it was possible to determine the glass transition temperature (Tg) of the pre-preg and the percentage of final polymerization.