PET bottle recycling and filament production for 3D printing: design and development of a sustainable extrusion system

Abstract

The widespread use of plastics, particularly polyethylene terephthalate (PET), has created both economic opportunities and severe environmental challenges. As plastic consumption continues to rise globally, innovative recycling and reuse strategies become essential to mitigate the ecological burden of plastic waste. One promising approach is the repurposing of PET bottles into usable 3D printing filament, thereby transforming waste into value-added products. This paper presents the design and development of a PET recycling and filament manufacturing system for 3D printers. The work integrates knowledge of polymer chemistry, thermomechanical design, and additive manufacturing, with an emphasis on environmental awareness and sustainability. The system is designed to cut, shred, and extrude PET waste into filament suitable for Fused Deposition Modeling (FDM) printers. Experimental results demonstrate the feasibility of producing consistent filament diameters with acceptable mechanical performance, though several material-related challenges remain. This study contributes to circular economy practices by promoting localized recycling, enabling decentralized filament production, and reducing both environmental impact and raw material costs.