Coming Full Circle: Innovating towards Sustainable Man-Made Cellulosic Fibres
Introduction
The importance of MMCF production remains a challenge
Man-made cellulosic fibre (MMCF) are a group of fibres that are conventionally derived primarily from wood, and in some cases other sources of cellulose, such as bamboo or other plant matter. Cellulose is found in the walls of plant cells, helping plants and trees to stay upright. It is also a key component of cotton fibres, in which it is found in extremely pure form. Cotton is an example of a ‘natural’ cellulose fibre and is processed differently from MMCF – with the latter following a dissolution and extrusion process, thus being referred to as ‘man-made’. In the majority of MMCF production, wood is mechanically shredded and then processed multiple times into sheets of cellulosic ‘pulp’. These sheets are then dissolved to form a viscose solution, which is extruded through spinnerets in a wet spinning process into fibre.
Man-Made Cellulosic Fibres (MMCF) are the third most commonly used fibre in the world, behind polyester and cotton. With an annual production volume of approximately 7.1 million tonnes, MMCFs constitute around 6.4% of the total fibre production volume1. Perhaps more telling of MMCF’s significance in the global fibre market are their rate of growth – the production volume has more than doubled from just over 3 million tonnes since 19902. This rate of growth is not expected to subside, with Textile Exchange forecasting a Compound Annual Growth Rate (CAGR) of over 6% in MMCF production between 2019 & 20223. In comparison, it is forecasted that cotton fibre will grow at a CAGR of approximately 3% between the period of 2019 to 2024 – further demonstrating MMCF’s increasing significance4.
MMCFs encapsulate a range of different fibres – all possessing different performance characteristics and different environmental impacts. Viscose has 79% share of production volume, with acetate holding 13% (its primary application being non-textile).
Lyocell has a 4.3% market share; however it is estimated to grow at a CAGR of approximately 15% in the coming years, which is the fastest of any MMCF5. Lyocell’s rapid forecasted growth can be put down to two main factors: first, the manufacturing process is less chemically intensive than viscose and does not use toxic compounds as reagents (e.g. carbon disulphide), leading to a 99.7% solvent recovery rate6. Second, as a fibre it has greater strength compared with viscose and cotton.
Modal and cupro make up the last two types of MMCFs, contributing a market share of 2.8% and less than 1% percent respectively.
A SHORT HISTORY OF LYOCELL
Lyocell was first commercially produced in the early 1990’s by Courtaulds Fibres in the UK, marketing the lyocell fibres under the brand name ‘Tencel’. The patented process was later acquired and further developed by Lenzing; however, since then other large MMCF producers have entered the space. Notably, in February 2019 Birla Cellulose commissioned a new plant that will double its lyocell capacity and Sateri announced a 20,000 tonne per annum capacity lyocell production plant in Shandong, China.
According to Canopy, today there are 42 dissolving pulp mills providing across 17 countries, with more than half located between Brazil, Indonesia, China, USA, South Africa and Canada. In the fibre production stage, China dominated the MMCF production – manufacturing two thirds of all MMCFs, with USA, India, Austria and Indonesia all producing between 4% – 8% of man-made cellulosic fibres7.
With regards to the organisations behind the market, the 2019 Canopy Hot Button Report revealed that the Chinese Sateri (part of Royal Golden Eagle Group) has the largest proportion of global production capacity, holding a market share of almost 16% in 2019. The globally operating Austrian headquartered Lenzing held the second largest market share of almost 15%, with Indian Aditya Birla Group’s Birla Cellulose holding close to 13%. Finally, Tangshan Sanyou’s production accounted for almost 12% of the viscose production – thus demonstrating that four organisations account for over 50% of the global total viscose production8.
MMCF production has great potential from a sustainability perspective; moving production away from oil-derived synthetic fibres and reducing the depletion of freshwater through reduced cotton cultivation. Furthermore, MMCF commands considerably less land-usage than cotton, as well as no pesticides or insecticides. However, imperative to the sustainability credentials are responsible sourcing practices and production processes, such as replanting forests at a faster rate than harvesting, and recovering the chemicals used in production in a closed-loop manner.
Canopy estimated that approximately one third of MMCF still comes from ancient and endangered forests9. To put that into context, the viscose fibre produced in 2019 translates into the cutting of 150 million trees, meaning that roughly 50 million could have originated from ancient and endangered forests10. Moreover, complementary to more responsible sourcing is incremental improvement in production processes and alignment to industry standards, as well as disruptive innovation. Only then, with all elements working together, will we transition to a more sustainable and circular MMCF industry.
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