Researchers at Queen’s University Belfast are pioneering innovative manufacturing techniques to turn single-use plastic waste such as used milk bottles into products including storage tanks for water and fuel, and sporting goods such as kayaks and canoes.
Today, the world produces over 300 million tonnes of plastics every year, which is almost equivalent to the weight of the entire human population.
The project is funded by Innovate UK through its “Plastics Innovation: Towards Zero Waste” Programme and the researchers are working in collaboration with three industrial partners; Impact Laboratories Ltd, Scotland, Impact Recycling Ltd in England and Harlequin Plastics Ltd, Northern Ireland.
Dr Peter Martin, from the School of Mechanical and Aerospace Engineering at Queen’s, explained: “The process starts with flakes of waste plastics being separated and compounded into pellets using the patented technologies of Impact Laboratories and Impact Recycling.
“At Queen’s, we take these pellets and grind them into a fine powder, which is then blended with a proportion of new plastic (polyethylene), heated to over 200ºC and then cooled within a mould to transform it into the shape of a new product.”
“Our research involves testing to find the optimum combination of blending the plastics and processing conditions so that eventually Harlequin Manufacturing will be able to introduce a range of new rotomolded products made largely from post-consumer waste.”
It is expected that in one product of this kind, waste plastic could replace around 30% of the new plastic required and use the equivalent of 1,000 old milk bottles in its manufacture.
'More sustainable era'
Mark Kearns, Moulding Research Manager at PPRC at Queen’s, added: “The rotational moulding process is unique in comparison to other plastic forming methods since it is used to manufacture large products that typically use very large volumes of plastics.
“The ability to condense and transform large volumes of recycled plastics into products designed to last many years will result in a substantial reduction in the amount of post-consumer waste going to landfill, rivers and the ocean.”
“It will also help to reduce the quantity of pure polyethylene used in the process, ushering in a new and more sustainable era in the production of rotationally moulded plastics.”
Rotocycle is a £500,000 project — funded by Innovate UK — which began in January 2019 and will last for two years.
Nick Cliffe, Interim Deputy Challenge Director of Smart Sustainable Plastic Packaging, at UK Research and Innovation, said: “Plastics have transformed the modern world in many positive ways.”
“Yet today, we are increasingly conscious of the devastating damage plastic waste can inflict on our planet and the wellbeing of people and wildlife,” Cliffe concluded.