Mechanical Safety of Re-injected Carbon Fiber Reinforced Acrylonitrile-butadiene-styrene Components in Transportation Applications

The transport industry increasingly seeks materials that balance environmental sustainability and mechanical safety. This study investigates the impact properties of carbon fiber (CF) reinforced acrylonitrile butadiene styrene (ABS) composites, which are a promising candidate for lightweight structural elements in transportation. Specimens of pure ABS and ABS+CF composites (1 wt%, 3 wt%, 5wt% CF) were evaluated in initial and repeated injection cycles using standardized Charpy impact tests according to ISO 179. A technologically simple and cost-effective method was used based on the re-injection of grit obtained from the initially injected composite. The results showed a consistent decrease in Charpy impact strength with increasing CF content, reflecting the brittle nature of CF. However, the maximum impact force values remained relatively stable, indicating the influence of CF primarily on energy absorption rather than on resistance to maximum force. Re-injection reduced energy absorption for most groups but also improved structural homogeneity and interfacial bonding in selected cases. These findings highlight the critical trade-offs between recyclability, mechanical properties, and material safety in sustainable transportation.