1. Manmade Cellulosic Fibers (MMCF)—A Historical Introduction and Existing Solutions to a More Sustainable Production

Forecasts of the use of manmade cellulosic fiber (MMCF) like viscose suggest a rise in the next few years, due to its performance and price compared with other fibers. MMCF, such as viscose/rayon, lyocell and modal (as well as cupro and acetate), are the second most important group of cellulosic fibers after cotton, with an average annual demand of 5–6 million tons. MMCF is produced from natural feedstock such as trees and plants using a chemical process, unlike cotton. Recent reports from non-governmental organizations (NGO), like Canopy. On the nature of viscose production, covering the sourcing and origin of feedstock, the threat to endangered species and environmental pollution created by the pulp and fiber production process, raised awareness among textile and apparel companies. Dissolved pulp used for MMCF production, sometimes from controversial or illegal sources, is transformed or regenerated into fiber by a water, chemical and energy intensive, multiple step process using highly toxic chemicals. Although the process is more than 100 years old, the industry still relies on the very same kind of toxic chemicals considered dangerous for the environment and humankind. The production of lyocell fiber uses a different chemical process which is considered eco-friendly. In their 2017 and 2018 reports, the Changing Markets Foundation claim that the Viscose industry is using non-sustainable feedstock and that fiber production in Asia heavily pollutes the environment and is endangering human health. One life cycle assessment (LCA), commissioned by the brand Stella McCartney, evaluating the impact of ten different variants of MMCF global production, it was concluded that the current viscose production system carries very different but serious risks. All this underlines the need for a more sustainable sourcing of feedstock for dissolving pulp as well as more sustainable production processes for MMCF that include alternative feedstocks, better control and efficiency of inputs as well as a better management of the manufacturing process, including waste water, solid waste and air emissions. Alternative feedstock and recycled feedstock include pre- and post-consumer textile waste but also non-textile feedstocks such as agricultural residues or even manure. So far alternative feedstocks play a marginal role. Even though technologies seem ready, a significant investment is required scale them to a commercial level. The following chapter will reflect on the pros and cons of MMCF production processes and will provide some possible solutions to a more environmentally friendly future for MMCF. This chapter cannot claim to be complete nor comprehensive. In a constantly evolving industry, we highlight some relevant innovations where industry success and scaling potential still needs to be proven. It is imperative that more scientific data on sustainability attributes and impact on the environment, through independent LCAs, for example, need to be gathered in order to allow assessment and better comparability.