Once prized for its softness and versatility, viscose is now under scrutiny: this semi-synthetic fiber reveals a complex story of innovation, comfort, and environmental cost.
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A Brief Introduction to Viscose
For more than a century, cotton has dominated the textile industry. But as climate pressures and supply chain instability mount, manufacturers have turned to alternatives. Chief among them is viscose, also known as rayon. Though its origins lie in wood pulp, not oil, viscose occupies a grey area between natural and synthetic, and its production is somewhat complicated.
Known as viscose in Europe and Rayon in the United States, this material is a cellulose-based, artificially synthesized fiber used worldwide.1 In comparison to other manmade fibers, viscose is not made from artificial material. Instead, it is developed by processing wood pulp, like bamboo, a natural cellulose-based material, and it has properties exceptionally similar to natural cellulosic fibers like cotton or linen.2
Unlike fully synthetic materials, viscose is soft and absorbent, with excellent dyeability, draping, and breathability. These properties have made it a widespread fabric choice in the textile industry.3,4
But this versatility comes at a chemical cost. Turning trees into fiber involves a highly engineered sequence of reactions, beginning with the pulping of wood and ending in wet-spinning threads of regenerated cellulose.
Manufacturing Process
Manufacturing viscose begins with extracting cellulose from wood pulp. A typical source is SAPPI Saiccor’s short-fiber eucalyptus and acacia mix. The pulp is processed using an acid sulfate method and then bleached without elemental chlorine. Another technique, the Kraft method, uses acid pre-treatment to strip the cell walls from the fiber.5
The resulting sheets of purified cellulose are steeped in a sodium hydroxide (NaOH) solution to create alkali cellulose. This is pressed and shredded into fine crumbs to increase its surface area and prepare it for further processing. The crumbs are then aged in steel vessels under controlled oxygen exposure.
This step can last anywhere from three to 72 hours, depending on the pulp mixture and the catalysts in the reaction. Whilst contained in the steel vessels, these crumbs break down into a lower molecular weight, a necessary step to ensure the material has the right viscosity for spinning.
Once the ageing process is complete, the resulting material is reacted with aqueous caustic soda, dissolving into a viscous solution, the origin of the fibers name.
This mixture is ripened at temperatures between 10 and 18°C for several days, during which the viscosity temporarily dips as it coagulates, before stabilizing. It is then filtered and degassed repeatedly to remove impurities and air bubbles that could disrupt spinning.
Before the essential spinning step, the solution must go through filtration and degassing to eliminate bubbles and solid particles that could clog and damage the equipment during spinning. The viscous solution is first passed through a series of filter presses as it moves toward large tanks where it is ripened. It is then similarly filtered several more times during transfers between containers.
During the spinning process, the viscose solution is carefully passed through a centrifugal pump or a spinneret into a spin bath that contains sulfuric acid (to acidify the sodium cellulose xanthate), sodium sulfate (to increase the bath’s salt content and speed up coagulation), and zinc sulfate (which reacts with sodium xanthate to form zinc xanthate, helping cross-link the cellulose molecules).
As the cellulose coagulates and regenerates, it solidifies into fine filaments. Simultaneously, the cellulose xanthate decomposes back into cellulose, forming the finished fibers.6
Finally, the fibers are washed to remove residual chemicals, cut to length, and dried. The result is a soft, breathable fabric used in everything from socks to bath towels.7
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Environmental Outlook
A key chemical used in this process is carbon disulfide. But it is a toxic compound that has been linked to neurological damage in exposed workers, as well as causing environmental contamination. Additionally, sourcing wood pulp for extracting cellulose to develop viscose involves cutting down trees, significantly affecting the ecological balance.8
A 2010 study comparing the environmental impact of manmade cellulosic fibers found viscose to be among the most damaging. The combination of land use, chemical waste, and water consumption stands in the way of it being a more environmentally friendly material.9
Closed-loop systems aim to capture and recycle harmful solvents, minimizing emissions and reducing the need for fresh chemicals. This can mean reducing bleaching, minimizing the ageing time, decreasing degradative steps, and lowering energy consumption.
Meanwhile, recent advances in textile recycling suggest that discarded viscose garments can be reprocessed into fibers nearly identical in quality to those made from virgin wood pulp, with strength and breathability rivalling those manufactured in typical processes.9
Some textile manufacturers are ahead of the curve, with their low-impact viscose materials.
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Despite viscose’s environmental shortcomings, its low cost and textile-friendly properties make it hard to replace outright. For now, researchers are continuing to refine processes. Tightening controls, improving recovery rates, and reimagining a fiber that continues to be used extensively in industry.
Further Reading
- Comnea-Stancu, I. et al. (2017). On the identification of rayon/viscose as a major fraction of microplastics in the marine environment: discrimination between natural and manmade cellulosic fibers using Fourier transform infrared spectroscopy. Applied spectroscopy, 71(5), 939-950. Available at: https://doi.org/10.1177/0003702816660725
- Shaikh, T. et al. (2012). Viscose rayon: a legendary development in the manmade textile. International Journal of Engineering Research and Application, 2(5), 675-680. Available at: https://www.academia.edu/download/37926049/Viscose_Rayon_A_Legendary_Development_in_the_Manmade_Textile.pdf
- Xu, Y. et al.(2007). Structure and thermal properties of bamboo viscose, Tencel and conventional viscose fiber. Journal of thermal analysis and calorimetry. 89(1). 197-201. Available at: https://doi.org/10.1007/s10973-005-7539-1
- Queensland University of Technology (QUT). (2025). Viscose. TextileR: Future Textile Industries. [Online]. Available at: https://research.qut.edu.au/textiler/knowledge-base/viscose/ [Accessed on: May 17, 2025].
- Woodings, C. (2001). Regenerated Cellulose Fibers. The Textile Institute. Woodhead Publishing, Cambridge, England. [Online]. Available at: https://books.google.com.pk/books?hl=en&lr=&id=U-akAgAAQBAJ&oi=fnd&pg=PA37&dq=How+Viscose+is+Made&ots=Gt4PLqa3qk&sig=5ttK34cE8WHCy8ezc85qXo3k0M4&redir_esc=y#v=onepage&q=How%20Viscose%20is%20Made&f=false [Accessed on: May 18, 2025].
- Textile Learner (2012). Production Process of Viscose Rayon. [Online]. Available at: https://textilelearner.net/viscose-rayon-manufacturing-process/ [Accessed on: May 18, 2025].
- Asia Pacific Rayon Limited (2022). How is Viscose Made? [Online]. Available at: https://www.aprayon.com/en/media-english/articles/how-is-viscose-made/ [Accessed on: May 18, 2025].
- Forsberg, D. et al. (2024). Towards Sustainable Viscose-to-Viscose Production: Strategies for Recycling of Viscose Fibres. Sustainability, 16(10), 4127. Available at: https://doi.org/10.3390/su1610412
- Shen, L. et al. (2010). Environmental impact assessment of manmade cellulose fibres. Resources, Conservation and Recycling, 55(2), 260-274. Available at: https://doi.org/10.1016/j.resconrec.2010.10.001
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