‘This is the missing piece of PE recycling and the circular economy.’
An international team of scientists; led by the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, US, have spun polyethylene into fibres and yarns which can wick away moisture. They estimate that the silky fabrics created from these yarns may have a smaller environmental impact over their life cycle than cotton or nylon textiles.
Publishing their work in Nature Sustainability, the researchers also hope that fabrics made from polyethylene could provide an incentive to recycle plastic bags and other polyethylene products into wearable textiles.
Overcoming polyethylene’s lack of absorbency, the research team found that taking the polymer’s powder form, and using standard textile manufacturing equipment to melt and extrude it into thin fibres, caused the polymer to become weakly hydrophilic. When the fibre was turned into a yarn, the spaces between the fibres formed capillaries through which water molecules could be passively absorbed. After optimising the fibres wicking ability, it was found that the polyethylene yarn wicked away and evaporated water faster than other common textiles.
In addition, colour could be added to the fibres by placing coloured particles in with the powder before extruding. This dry colouring process contributes to the relatively small ecological footprint of the polyethylene fibre. It was also noted that washing and drying the material required less energy when compared with cotton and other textiles.
Svetlana Boriskina, a research scientist in the Department of Mechanical Engineering, MIT said; ‘We can colour polyethylene fibres in a completely dry fashion, and at the end of their life cycle we could melt down, centrifuge and recover the particles to use again.’
The team is exploring ways to incorporate polyethylene fabrics into lightweight, passively cooling athletic apparel, military attire and even next-generation space suits.
Dr Shirley Meng, Professor of NanoEngineering and Material Science at the University of California at San Diego, US said; ‘Based on the data presented in the paper, the particular PE fabric reported here depicts superior properties than those of cotton. The main point is that recycled PE can be used to make textile, a product with significant value. This is the missing piece of PE recycling and the circular economy.’ Dr Meng was not involved in the research.