Investigating thermal and free vibrational properties of fabric sandwich composite materials for car hood application

Textile fabric wastes are the second most polluting materials in the world after plastic. This study investigated the thermal and free vibrational properties of the sandwich composites prepared from recycled fabric materials. Grey cotton fabric(C) and wool garment waste (G) reinforced a polyester matrix in a different layer arrangement (CCCC, CGCG, CGGC, GCCG, GGGG, and chopped). Thermogravimetric analysis (TGA) and dilatometry were performed to determine the thermal properties. TGA results showed similar initial weight loss for GCCG, CCCC, and CGGC (within a range of 25 °C–800°C) and for GCGC, GGGG, and chopped arrangements. All composites exhibited thermal stability up to 305°C. Between 310°C and 405°C, a gradual mass loss was observed, followed by more significant degradation above 405°C and residual mass loss observed at 655°C. Dilatometry tests reveal minimal volume change up to a heating temperature of 300°C for all durations (20 min, 40 min, and 60 min). In addition, the free-vibration analysis indicated poor energy-absorbing properties for CCCC, while CGGC sandwich composite specimen exhibited better energy-absorbing properties. Based on these results, it can be concluded that these composite materials are suitable for applications such as car hoods, which typically function below 105°C temperatures.