New Ways To Reuse Plastic Pioneered At QUB

As the world grows more conscious of plastic pollution, researchers at Queens University Belfast are pioneering new methods to transform single-use plastic items into a range of useful products.

Waste items such as used milk bottles are being repurposed into products there is already a market for, such as sporting goods like kayaks and canoes or storage tanks for water and fuel.

Each year, 300 million tonnes of plastic are produced throughout the world, the equivalent of almost the entire weight of the human population. A huge amount of waste then results from the items that are single-use and not recyclable, with this going into landfill and often entering the natural environment and polluting oceans.

Researchers at the QUB Polymer Processing Research Centre (PPRC), which has led the way in plastics recycling for over 30 years, are at the forefront of pioneering innovative manufacturing techniques to mould waste plastic into a variety of useful products.

Their ground-breaking approach involves a manufacturing process called rotational moulding, which has the potential to economically recycle very large volumes of plastic waste into a wide variety of innovative products such as urban street furniture, storage tanks and marine buoys.

Dr Peter Martin, from the School of Mechanical and Aerospace Engineering, explained: "Our engineers are working on novel techniques that could really help to tackle the huge global issue of single-use waste plastics.

"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."

Dr Martin adds: "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 rotomoulded products made largely from post-consumer waste.

"It is expected that in one product of this kind waste plastic could replace around 30 per cent of the new plastic required and use the equivalent of 1,000 old milk bottles in its manufacture."

Funded by Innovate UK's 'Plastics Innovation: Towards Zero Waste' Programme, the researchers are working in collaboration with three industrial partners; Impact Laboratories Ltd in Scotland, Impact Recycling Ltd in England and Harlequin Plastics Ltd in Northern Ireland.

At present, the UK rotational moulding industry alone consumes more than 38,000 tonnes of new plastic, of which more than 11,000 tonnes could be saved.

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.

"This new process will therefore have significant environmental benefits. 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 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.

"The Plastics Research and Innovation Fund will help help address these vital issue and projects such as Rotocycle will play a key role in this global effort."



(JG/CM)