Renewable Raw Material
Most of the man-made fibres (MMF) are made out of synthetic polymers where the feedstock is oil-based.
However, some MMF are also based on renewable resources. Viscose, Lyocell, Rayon and Modal are typical and important MMF which are based on wood – the renewable resource. Cellulose is the world’s most important biopolymer by far. About half of the global biomass consists of cellulose, being an amazing unique biopolymer. Wood is converted into pulp, and pulp into fibres.
The pulp and fibre industry is part of the natural carbon cycle. Cellulose is created during plant photosynthesis; carbon dioxide and water are converted into organic matter. The process is powered by sunlight, and the exhaust product is oxygen. Cellulose is nature’s most important construction material – natural global production is about 40 billion tons per year.
Unless cotton, cellulosic man-made fibres do not compete with food production. Only 0.2 % of wood felled globally are used for the manufacture of cellulosic man-made fibres. Furthermore, wood used for this purpose comes from sustainably managed plantations or marginal productivity areas that are unsuitable for food crops due to soil conditions, anyway.
Fuelled by the discussions on sustainability, a small but growing proportion of man-made fibres production is based on innovative raw material sources such as corn or vegetable oil. Typical examples are PLA fibres, and the use of bio-propanediol (PDO) out of corn, as a substitute for the oil-based PDO, for the polymerization of PTT polyester.