شهاب الدين گرشاسبي

Plastic materials are among the most widely used substances in the world, and their quantity continues to increase due to population growth and industrial development. The pollution of the planet has compelled humanity to recycle plastics and contribute to preserving a green environment. Among the innovative approaches, the use of recycled plastics as raw materials for 3D printers stands out. This research aims to present existing recycling methods and additive manufacturing processes—specifically Fused Deposition Modeling (FDM)—using recycled and composite materials based on PET, to produce functional parts with desirable properties. Initially, the feasibility of using various plastics, the history of 3D printing, prior studies, and some necessary fundamentals were reviewed. Subsequently, the processes for producing recycled filaments and the key parameters influencing the quality of 3D-printed components were detailed. To eva‎luate mechanical properties, the Taguchi method for design of experiments was employed in uniaxial tensile tests, and the shape memory behavior of PET-based recycled polymers was also examined. The results demonstrated that processing conditions during filament production and 3D printing significantly affect the final properties. Both intrinsic and extrinsic parameters involved in 3D printing must be optimized to achieve parts with suitable properties. Reducing the printing speed to 30 mm/s and the layer thickness to 0.15 mm, along with increasing the nozzle temperature to 245°C and setting the bead width to 0.96 mm, led to an ultimate tensile strength of up to 42.903 MPa and an elastic modulus of 7.833 GPa in printed samples made from PETG+CF composite filament. A novel infill strategy improved tensile strength by 10% and elongation at break by 300%, though stiffness decreased by about 37% compared to the conventional method. Samples printed from rPET+rHDPE recycled filament showed 6% higher ultimate tensile strength than those made from PETG+CF, while stiffness remained comparable. Furthermore, both materials demonstrated over 90% shape memory behavior in flexural tests, indicating promising potential in the field of shape memory polymers. In conclusion, Fused Deposition Modeling using recycled feedstock—including PET-based recycled and composite materials—can be considered a sustainable and high-potential approach for environmental preservation, while achieving satisfactory mechanical performance.

چاپ سه‌بعدي روش رسوب ذوبي , پت (پلي اتيلن ترفتالات) بازيافتي , پايداري محيط زيست , پليمرهاي حافظه دار , رشته كامپوزيتي

FDM 3D-Printing , rPET (recycled Poly Ethylene Terephthalate) , Sustainability , SMP (Shape Memory Polymers) , Composite Filament

Shahabeddin Garshasbi

Mahmood Mehrdad Shokrieh