Turning ocean plastics into new textiles by melt spinning
Textiles are the most exciting material one can possibly work with – or so some of us think! Starting from eternally long and super-thin fibres, we can produce fabrics that provide warmth, protection and make us feel good-looking. In addition, textile fibres are used in numerous technical applications, for example fishing nets.
Last week we had an exciting day at work, spinning new textile fibres from old fishing nets! Recycling is increasingly on the agenda of the textile industry, as it very well should be considering that textile production today relies almost solely (>97%) on virgin feedstock. Moreover, nearly three quarters of used garments end up being incinerated or landfilled.
Melt spinning is the most common way to produce textile fibres industrially. This simple yet effective method involves pushing a polymer melt through tiny holes and then stretching it into fibres of some 10 micrometres in diameter. The fibres are collected at a rate of several kilometres per minute, making it a highly efficient process. The most common materials used for melt spinning are polyester and polyamide, which are predominantly derived from fossil fuels.
An alternative feedstock for new textiles may be recycled textiles such as discarded fishing nets, which are originally produced from high quality polyamide. The research project OCEAN-LSAM (originated from Ocean Tech Hub LDA in Portugal and today led by Chalmers University of Technology) aims to develop a global network of circular economy microfactories that recycle local polymer waste streams into new raw materials. At Ocean Tech Hub, end-of-life fishing nets from local small commercial fishermen in Peniche, Portugal are collected, washed, sorted and finally compounded into granules, suitable for (among other processes) melt spinning.
In general, spinning fibres from recycled feedstock can be challenging. Due to the high speed and precision of the melt spinning process, inhomogeneity and impurities (which are common in recycled materials) can affect the quality of fibres or simply make spinning impossible. Therefore we were very happy to find that granules made from fishing nets could be used as a source for fibre spinning! Not only can we turn waste into a valuable resource and progress towards a more circular economy, we can also contribute to reducing ocean plastics and the harm these discarded materials can cause to sea creatures, including entanglement and starvation through ingestion.