DEVELOPMENT AND CHARACTERIZATION OF 3D PRINTING FILAMENT DERIVED FROM RECYCLED PET BOTTLES

Abstract

The increasing generation of plastic waste has created significant environmental concerns, particularly due to the improper disposal of polyethylene terephthalate (PET) bottles. This study presents the development of a low-cost extrusion system for converting waste PET bottles into material suitable for 3D printing filament production. The proposed system uses manually cut PET bottle strips as feedstock, eliminating the need for a conventional plastic shredding unit. The PET strips are heated and melted within an approximate temperature range of 240–260◦C and subsequently extruded through a 4 mm nozzle. A 12 V DC geared motor operating at 10 rpm is employed for pulling and winding the extruded material, while natural air cooling is used for solidification. The influence of processing temperature and pulling speed on filament continuity, surface appearance, and approximate diameter consistency is investigated. Experimental observations indicate that continuous filament can be produced when the heating and pulling conditions are appropriately controlled. Higher pulling speeds generally produce thinner filament, whereas lower speeds tend to produce thicker filament. The developed system demonstrates the feasibility of a simple and economical approach for recycling PET bottle waste into 3D printing filament and provides a foundation for further improvements in automated diameter control, cooling, and material characterization.