UV Exposure Affects Tenacity Of Polyester Fibres

- Jan 31, 2018 -

Continued exposure to UV light can lower the tenacity of some polyester fibres by up to 42%, new research has shown.

Microfibres released from clothes during both the manufacturing and the consumer wash and wear stages, have been found to have detrimental effects environmentally. Initially assumptions from the industry pointed at fleece fabrics as the main contributor, but driven to challenge this deeper within textile engineering, the campaign #DontFeedTheFish was launched in January 2017 to take research to the polymer, fibre and yarn level.

Backed by the industry at the brand, non-profit and supplier levels, detailed research by material futurist, Sophie Mather of Biov8tion, studied polyester yarns in lab conditions under various situations to assess breakage behaviour patterns. Work concluded that UV exposure and yarns of a smaller denier are both considerable factors in lowing tenacity in polyester.

UK-based Biov8tion works with brands and retailers like M&S, Nike and H&M on sustainable innovation, and projects designed to reduce the impacts of water, waste and carbon across the total textile and apparel process from raw material to end of life. 

The key learning from this latest entry-level research found UV exposure to be a significant trigger on lowering tenacity in polyester. A lower tenacity of yarns at the garment level would mean that polyester fabrics are more prone to fibre fragmentation after UV exposure. Such an observation was consistent across the varying yarn specs tested, with up to 42% tenacity reductions after 72 hours of UV exposure.

The research was backed financially by the Outdoor Industry Microfibre Consortium, with industry-based support for the campaign spearheaded by key brands including The North Face, Adidas, Asos, Berghaus, Finisterre, Kering and Marks and Spencer, amongst others.

"Brands have a duty of care to make steps to ensure that the clothing we make is well designed and well made, and mindful of the impact of our sourcing decisions," said Deborah Luffman, product director, Finisterre.

During the study, researchers used a  range of yarn sizes from 30 to a 150, focusing on 100% polyester filament samples which were sourced from key industry suppliers. A selection of 40 samples were studied, with tenacity measured both before and after 72 hours of UV exposure. Meanwhile. the effect that differences in yarn specification played on breakage also came under scrutiny. 

Three subsequent pieces of work have since developed at both research and industry levels.

  • The area of recycled versus virgin raw materials has been taken into a deeper piece of research in order to work towards concluding if virgin or recycled differ in regard to fibre release.

  • A correlation of yarn results with corresponding fabric structures is being conducted in order to better understand the interconnection between yarn and fabric construction.

  • Work carried out in collaboration with supply chain partners, has been kick-started to look at how these results can be used to support future product solutions at the yarn level.

Researchers say the project has successfully demonstrated a need to elevate research and development from the ground level (polymer) upwards to include fibres, yarns, and subsequent processing stages within the textile industry.