Sustainable additive manufacturing of polymers and composites: optimization of nozzle design, printing parameters, and post processing for waste to value transformation

Additive manufacturing using fused deposition modelling (FDM) has emerged as a versatile and resource-efficient route for producing complex polymer and composite structures. However, the quality and sustainability of FDM-printed components are strongly governed by process parameters, nozzle design, and post-processing methods. This review provides a systematic analysis of these factors and their combined influence on mechanical integrity, surface finish, and dimensional accuracy. The study highlights how optimized layer thickness, build orientation, and extrusion temperature enhance interlayer adhesion and structural performance, while advanced nozzle geometries improve melt flow and minimize material waste. Post-processing techniques such as annealing, chemical smoothing, and surface finishing are evaluated for their roles in extending product life cycles and enabling recycled or bio-based polymer feedstocks. By linking process optimization to energy efficiency and material utilization, this review positions FDM as a pathway for sustainable, waste-to-value additive manufacturing. The insights presented support the development of eco-efficient design frameworks for next-generation polymer and composite processing within circular engineering systems.