Indian Researchers Patent a $470 Extruder That Turns Plastic Waste Into 3D Printer Filament

Researchers at the National Institute of Technology Rourkela have secured a patent for a portable extrusion system that converts recycled plastic waste into composite filament for FDM 3D printing. The system costs roughly 45,000 rupees to build, which comes to about $470, and the five-person team from the institute's mechanical and chemical engineering departments says it is ready for labs, schools, and small manufacturers.

The patent, application number 202431068691, covers a process that combines a controlled cooling stage with PID temperature controllers. The tighter temperature control gives the extruder better control over filament formation as the material cools, producing a composite the researchers say is stronger and more durable than recycled filament made without that step.

Why Recycled Filament Has Struggled to Gain Traction

Recycled plastic has been proposed as a solution to filament cost for years, but it rarely works in practice. Reprocessing waste into usable filament tends to introduce its own costs, creates material loss, and often produces a spool with inconsistent strength. Weak spots, rough surfaces, and dimensional drift all trace back to inconsistent material, which keeps FDM printing tethered to commercially produced virgin-plastic filament even as demand grows and prices climb.

Sandhyarani Biswas, associate professor in the Department of Mechanical Engineering, called the system a significant advancement in filament production that could yield parts with improved mechanical properties while benefiting the environment.

Sujit Sen, professor in the Department of Chemical Engineering, said the system is designed to process various types of plastics into usable 3D printer filament. The institute frames the approach as part of a circular model, recycling plastic waste repeatedly into valuable products rather than discarding it.

A Low-Cost Path to In-House Filament

The machine can handle multiple plastic types, blending recycled particles with reinforcement materials to produce a composite that met the team's dimensional accuracy and mechanical property requirements in lab testing. That flexibility matters for makers who want to control their supply chain without investing in industrial-grade equipment.

At $470, the system sits well below the price of any commercial filament extruder on the market. For schools and community makerspaces, it could remove a longstanding barrier to running a fully closed-loop plastic recycling operation alongside a 3D printing farm.

The patent lists five inventors: Biswas and Sen alongside Jagdish Uday Khatu, Himanshu Singh, and Kiran Suna. The team collaborated with Universite de Lorraine in France on aspects of the research.

No commercial release has been announced. The patent protects the specific extrusion and cooling configuration, which means anyone replicating the setup for commercial purposes would need to license the technology from NIT Rourkela.