Advancing Sustainable 3D Practices

About the Project

As part of the UK RAS STEPS programme, this project focusses on addressing a growing challenge across the sector – waste from 3D printing.

Many institutions use 3D printing for rapid prototypes and finished parts using PLA plastic filament. This process often involves multiple design iterations, creating plastic waste.

Our goal is to recycle these parts into usable plastic sheets for laser cutting – or even back into filament – to reduce our plastic waste and carbon footprint.

Why It Matters

3D printing is fast, accessible, and ideal for prototyping – but it can lead to excessive waste, especially when design processes involve multiple iterations. This project tackles waste at both the source and after the fact, aiming to:

• Reduce plastic waste and carbon footprint
• Extend the life of 3D-printed materials
• Develop easy-to-replicate recycling processes
• Encourage better design thinking in rapid prototyping

In November 2024, through the UK RAS STEPS scheme, the National Robotarium at Heriot Watt University welcomed technicians from the University of York and Imperial College London for a week-long knowledge exchange placement.

They joined efforts already underway to explore recycling PLA waste using basic tools like a t-shirt heat press and a manual plastic shredder. With their help, progress was accelerated and the team successfully created recycled plastic sheets that could be laser cut into functional components.

1. Sort & Store
   Currently, only PLA filament is recycled – it’s the most common, cheapest, and easiest to process. We remove all contaminants such as glue, silicone, metal inserts, and screws
2. Shred
   3D print waste is broken down and shredded into 4–8 mm chips using a hand or electric shredder. Large parts are broken down into tennis-ball-sized chunks first.
   
3. Reform
   The shredded PLA is placed in a custom aluminium frame between non-stick baking sheets and pressed at 220°C using a t-shirt heat press.
   • Each side is heated for about 10 minutes
   • Sheets are then cooled under pressure to prevent warping
   • Final size: 370mm x 370mm x 3mm (thicker if needed)

   

4. Laser Cut
   The hardened PLA sheets can be laser cut using standard acrylic settings, enabling us to create drill jigs, templates, and more.

We’ve made the process as replicable as possible:

• Aluminium frame: Flat bar + 3D-printed corners
• Heat press: 374mm x 374mm recommended (if using a different heat press, your sizes may need to change!)

What to buy (to make 3mm thick sheets)

Option of Electric shredder

Drawings

Aluminium Flat bar 12mm x 3mm x 384mm long with holes (4 off required)

If you would like files on how to print the aluminium frames, please contact info@ukras-steps.org

Risk Assessments

1. Risk Assessment – Shredder basic v1
2. Risk Assessment- T-shirt Press

The process involved trial, error, and experimentation. Some key takeaways:

• PLA must be dry and clean to reform successfully
• Shredding and melting behaviours vary between printed parts and “spaghetti” extrusion waste
• Shredder feeding works better slowly and steadily
• Heat press fumes may require ventilation – further investigation needed

This project is a great example of how UK RAS STEPS secondments can spark long-term innovation. Our next steps include:

• Standardising the plastic volume per sheet
• Testing fume extraction solutions
• Exploring automation of the process
• Investigating other reuse opportunities (e.g., injection moulding)
• Rethinking the design process to reduce waste at the source

We’re working on a shareable web resource and process guide for anyone interested in replicating or improving the project. If you’re a technician, maker, or researcher curious about waste reduction, we’d love to hear from you.

This project proves that with a little creativity and collaboration, even waste can become a resource.

For more information, and to join the group, email info@ukras-steps.org.uk