Enhancing Resource Efficiency in PA6.6-GF30 Composites: Leveraging Processing-Induced Anisotropy for Sustainable Structural Design and Material Savings

Improving resource efficiency in structural polymer components requires manufacturing strategies capable of enhancing mechanical performance without increasing material consumption. In this study, the influence of processing-induced fiber architecture on the dynamic fracture toughness of short-glass-fiber-reinforced polyamide 6.6 (PA6.6-GF30) was investigated as a potential strategy for improving structural efficiency through microstructural design. Two materials with identical polymer matrix and glass-fiber content, manufactured by compression molding and injection molding, were evaluated using instrumented Single Edge Notched Bend (SENB) impact tests under Linear Elastic Fracture Mechanics (LEFM) conditions. The effects of processing route, specimen orientation, and notch preparation method were systematically assessed. Compression-molded specimens exhibited pronounced anisotropy, with fracture toughness increasing from 2.30 MPa·m1/2 at α = 90° to 7.37 MPa·m1/2 at α = 0°, whereas injection-molded specimens showed a comparatively uniform response (4.19–4.77 MPa·m1/2). In contrast, notch preparation had only a minor influence on the measured fracture toughness. These results demonstrate that processing-induced fiber architecture is the dominant factor governing fracture toughness in PA6.6-GF30 and provide a mechanical basis for improving structural efficiency through optimized manufacturing. Although component-level structural optimization and life-cycle assessment were beyond the scope of this work, the findings indicate that tailoring the processing-induced fiber architecture may support future resource-efficient and circular design strategies for recyclable thermoplastic composites.