Researchers from Institute of Engineering and Rural Technology & Motilal Nehru National Institute of Technology Allahabad, Prayagraj, India, have developed and experimentally evaluated a filament extrusion system for converting waste polyethylene terephthalate (PET) into filament suitable for fused filament fabrication 3D printing. The study demonstrates a practical route for giving discarded PET a second life as a material for additive manufacturing.
The recycled PET filament was prepared from the post-consumer PET waste using the developed extrusion system. For reference material, PLA pellets were also taken to produce filament. The resulting filaments were then used to produce 3D printed specimens for mechanical testing.
The recycled PET specimens demonstrated competitive mechanical performance compared with PLA, highlighting the potential of recycled PET as a feedstock for filament-based 3D printing.
Plastic waste has become a growing environmental challenge, while additive manufacturing is creating increasing demand for polymer-based printing materials. One possible way of connecting these two challenges is to transform discarded plastics into new materials that can be used for 3D printing.
In a recent study published in Advanced Manufacturing, Amit Kumar Singh Chauhan, Utkarsh Mishra, Aryan Vinod Shukla, and Mukul Shukla developed a filament extrusion system specifically for processing recycled PET obtained from waste plastic bottles.
PET is widely used in everyday products, particularly beverage bottles, but discarded PET can remain in the environment for long periods if it is not appropriately recovered. Converting this waste into 3D-printing filament provides an opportunity to use an existing waste stream as a secondary manufacturing material.
The researchers first prepared waste PET by sorting, cleaning, drying, and shredding the discarded plastic. The prepared material was then processed using the fabricated extrusion system to produce filament. PLA pellets were also extruded using the same system to provide a comparison under similar processing conditions. The extrusion experiments showed that the fabricated system was capable of producing continuous polymer filament over appropriate processing conditions. The discharge behavior of both PET and PLA was examined at different temperatures, allowing the researchers to evaluate how processing temperature influenced material flow.
The recycled PET filament was subsequently used for 3D printing mechanical-test specimens. Tensile properties were evaluated and compared with specimens produced from PLA. The tensile strength of PLA specimens (44 ± 3.6 MPa) was found ~11% higher than PET (39 ± 3.2 MPa). Whereas, the percentage elongation of PET and PLA specimens were found as 4 and 5.2 % respectively. This performance affirms that recycled PET, when appropriately processed, can bridge the gap between environmental responsibility and mechanical functionality in 3D printing applications. This model will likely help industries improve their efficiency and performance by lowering the cost of the new materials and making it more efficient for them. The produced filament can create personalized accessories, household goods, and distinctive, tailored fashion products.
The study also highlights challenges associated with recycling PET for filament production. Moisture management and filament dimensional consistency remain important factors because variations during extrusion can influence printing quality and the mechanical performance of printed components.
Beyond the individual extrusion system, the work demonstrates a broader concept: waste plastic can be redirected from disposal toward productive use in additive manufacturing. Localized recycling and filament production could be particularly relevant for educational institutions, research laboratories, makerspaces, and other settings where polymer waste and 3D-printing activities coexist.
The researchers emphasize that further optimization and material characterization will be needed before recycled PET filament can be considered a direct replacement for commercially manufactured filaments in all applications. Nevertheless, the demonstrated conversion of waste PET into functional 3D-printing filament provides a practical basis for further development of recycled polymer feedstocks for additive manufacturing.
This paper “Fabrication of a fused filament extrusion system for recycled PET and comparative mechanical characterization studies vis-à-vis PLA” was published in Advanced Manufacturing.
Chauhan A, Mishra U, Shukla A, Shukla M. Fabrication of a fused filament extrusion system for recycled PET and comparative mechanical characterization studies vis- à -vis PLA. Adv. Manuf. 2026(3):0001, https://doi.org/10.55092/am20260010.
Advanced Manufacturing
Experimental study
Not applicable
Fabrication of a fused filament extrusion system for recycled PET and comparative mechanical characterization studies vis-à-vis PLA
19-Aug-2026