Introduction
Plastic pollution collected during coastal clean-ups is typically difficult to recycle due to its mixed composition, degraded condition, and high levels of contamination. This Future Island-Island project, undertaken on Rathlin Island, Northern Ireland, with co-collaborator BIGsmall, applied a structured approach Beach Clean 2.0 to overcome these barriers by promoting sorting at source, improving material quality, and enabling targeted valorisation pathways.
CHALLENGE
During a citizen-led beach clean, samples were collected and analysed using infrared spectroscopy to determine polymer type and form. Significant volumes of polypropylene (PP) twine, polyethylene (PE) rope, and mixed rigid plastics were identified. Polypropylene twine was selected as a promising candidate for 3D printing filament production due to its polymer properties and relative abundance.
INNOVATION
To support source separation, a colour-coded bag system was introduced, allowing community volunteers to sort plastic waste by polymer family. The recovered PP twine was cleaned, dried, and manually fed into a twin-screw extruder by students participating in an international summer school. Although the initial extrudate varied in diameter, it was reprocessed to achieve a consistent filament width of approximately 1.75 mm, suitable for 3D printing.
RESULT
A simple test object was successfully printed using the filament on an entry-level 3D printer, demonstrating the technical feasibility of converting beach plastics into usable materials for additive manufacturing. This hands-on exercise also provided valuable experience in polymer processing, material characterisation, and circular design.
IMPACT
The project highlights the potential for locally collected marine plastic waste to be transformed into functional products, laying the groundwork for a repair and reuse culture on Rathlin Island. It also showcases how structured citizen science and educational initiatives can contribute to scalable circular economy solutions in coastal communities.