The potential for regenerated protein fibres within a circular economy: lessons from the past can inform sustainable innovation in the textiles industry

Humanity is currently facing a crisis of excess, with a growing population and the trend towards disposable goods, and the world’s resources are under tremendous pressure. This is especially evident in the textiles industry, with increasing consumer numbers and the trend of ‘fast fashion’ causing demand to be at an all-time high, with non-renewable feedstocks depleting and production of natural fibres also under strain. Considering the future of textile production, it can be beneficial to investigate our past for inspiration towards more sustainable approaches. Much of the research into regenerated protein fibres was performed out of necessity during wartime, and while this demonstrates the potential for food waste to be exploited as a resource, the manufacturing methods used at the time now present issues for a circular economy due to the high amounts of toxic waste produced. Using a range of historical and modern literature sources, including journal articles, patents and conference papers, this review presents the historical precedent and research performed into azlons, regenerated fibres produced from waste protein-rich materials. Historical evidence shows that the success of these azlon fibres was short-lived, partly due to negative associations with deprivation and hardship, alongside the emergence of alternative man-made fibres, which were devoid of these connotations with never-before-seen physical properties. The social and political climate leading to the creation, and ultimate demise, of azlons is explored along with the influence of evolving technologies and the marketing of these textile products to consumers. Although the creation of products from waste is not a new concept, the literature has identified that the synergy between the challenges faced in a time of resource scarcity and the current trend of problematic excess reveals an exciting opportunity to learn from our past to create a greener future. Lessons that could help with the current crisis within the textile industry are extracted and presented within the concept of a circular textiles economy. Our findings show that there is notable potential for one regenerated protein fibre, made from casein extracted from milk waste, to be manufactured within a localised, circular economy in conjunction with the principles of green chemistry and sustainable textiles technology.