Applying innovative research outcomes to address social issues and promote sustainable development have long been fundamental goals of PolyU. This commitment was exemplified by a recent Memorandum of Understanding (MoU) signed with the Correctional Services Department (CSD), focusing on food waste upcycling and the development of eco-friendly products to enhance sustainability within the correctional sector.

The MoU sets out a five-year framework for collaboration aimed at supporting the rehabilitation of persons in custody (PICs) while promoting environmental sustainability. In the initial phase, PolyU’s patented technology for producing 3D printing materials from discarded coffee grounds will be implemented in manufacturing work conducted by PICs. The initiative includes offering PICs access to vocational training in the design and production of sustainable products, thereby improving their employability. The training will leverage PolyU’s scientific research on upcycling food waste for industrial production within correctional facilities.

The food waste-derived 3D printing technology, developed by Professor Wong Ka-hing of the Research Institute for Future Food (RiFood), will be central to the initiative. This green solution combines spent coffee grounds and tea leaves with polylactic acid (PLA), to produce a material suitable for Fused Deposition Modelling (FDM) which is widely used in 3D printing.

The novel material, up to 50% which is derived from food waste, offers optimum printing performance. Tensile strength ranging from 10 to 40 MPa makes it suitable for a variety of applications, such as modular furniture and display items. It also boasts excellent ductility, which is ideal for shock-absorbing structures. Compliant with low-carbon policies, the customisable and scalable material requires no chemical additives during mass production and has a carbon footprint approximately 36% lower than that of traditional PLA materials.

The technology presents an innovative solution to challenges related to municipal food waste and greenhouse gas emissions. To foster a cohesive society and promote sustainable development, PolyU and CSD will work together to create a mutual aid ecosystem that generates new economic, ecological, and cultural value.

The eco-friendly products made from food-waste materials will be offered for sale on the CSD Sports Association’s “Made In Prison” online charity gift platform, encouraging public support for rehabilitation and environmental conservation. After covering essential expenses, all proceeds from sales will be donated to local registered charities, enabling PICs to contribute to the community.

Discover more about the food waste-derived 3D printing material here.