# Life Cycle Assessment of Fused Filament Fabrication Using Recycled Plastic and Carbon Fiber Composites

## TL;DR

This study evaluates the environmental impact of using recycled plastic and carbon fiber composites in 3D printing, showing significant reductions in CO2 emissions.

## Contribution

The study introduces a novel LCA framework for assessing recycled composite materials in FFF 3D printing.

## Key findings

- Recycled composite filaments show enhanced mechanical and thermal properties.
- The composite core achieves a net global warming potential of −12.55 kg CO2-eq.
- Challenges include material degradation and regional applicability of LCA models.

## Abstract

This study presents a comprehensive investigation into the application of Life Cycle Assessment (LCA) for advanced manufacturing and recycling processes, with a focus on achieving sustainability goals. The environmental and economic impacts of additive manufacturing (AM) and innovative recycling strategies for materials like carbon fiber-reinforced plastics (CFRPs) and 3D printing polymers are analyzed. Experimental efforts detail the preparation of recycled plastic–carbon fiber composite filaments suitable for Fused Filament Fabrication (FFF). The composite exhibits enhanced mechanical, thermal, and flame-resistant properties through optimal blending of plastic waste and carbon fibers. Sustainability assessments using Open LCA 2.2.0 and SolidWorks 2022 demonstrate significant environmental benefits aligned with circular economy principles. The analysis highlights that the weight reduction results in lifetime fuel savings combined with end-of-life credits of −1.32 kg CO2-eq for composite core versus +0.10 kg CO2-eq for plastic parts. The recycled composite achieves a net global warming potential of −12.55 kg CO2-eq, compared to +2.44 kg CO2-eq for plastic components. The study emphasizes challenges such as recyclability, material degradation, and regional applicability of global LCA models, while proposing pathways for future advancements.