A Green Opportunity for Viscose Processing in India

India is the second largest exporter of viscose behind China and in 2012, India produced 84.37 million kg viscose spun yarn. While the production of viscose fiber is relatively low compared to the 259.88 million kg of polyester spun yarn and the 3126 million kg of cotton, certain technologies may emerge to promote a sustainable viscoe processing in the near future.

Determining the sustainability of ‘end product’ in textiles is an extremely difficult task. Many variables along a supply chain can affect resource consumption. Fibers are spun, woven/ knitted, dyed and finished before they become fabric.   Further, wet processing of textiles is water and chemicals intensive and hence, the resource footprint is extremely specific to water hydrology, regulatory controls, and environmental management in the specific location where production is undertaken. 

Indicators like the Materials Sustainability Index (MSI) have attempted to rank materials by their sustainability performance (water/land, energy/GHG, chemicals and waste). 

Source: Material Sustainability Index

The above benchmarks are indicative as they do not take into account local environmental, and production process variations. It is still considered best to conduct a Life Cycle Assessment (LCA) due to the variability in processes and local production context. However,  LCAs require expensive data creation and data sharing which can be  difficult to facilitate across all members of a supply chain. 

As highlighted above, one of the processes to produce fiber is the viscose process. The viscose process can produce fibers from basically any cellulose or protein source like wood, cotton, bamboo, eucalyptus and even bacteria.  In the viscose process: 

• Cellulose is treated with sodium hydroxide and carbon disulfide, converting it into a highly viscous liquid. 
• The viscous fluid is then aged in order to break down the cellulose structures further. 
• The resulting mixture is forced through fine holes and a chemical bath where it hardens into fine strands. 
• After being bleached and washed it becomes yarn to be made into fabric. 

The largest producer of viscose fiber is India’s Aditya Birla Group (744 kilotons) followed by Austria’s Lenzing AG (710 kilotons) in 2010, sharing 30% of the total global viscose fiber capacity. Other similar considered more “sustainable” ways of creating rayon is using the Lyocell and Modal process which Lenzing AG has monopoly in both.   

The Journey of Viscose Processing & Sustainability

Most of the dialogue on sustainability of viscose processing has been around the source fibres used as part of the process, and therefore, the overall footprint of the end product. Traditionally wood or cotton was used with viscose process to produce rayon fabric. However, in  2003,manufacturers began using bamboo as an eco-friendly alternative to wood and cotton. This later received push back for falsely labelling bamboo-based rayon fabric as coming from “bamboo”. Indeed, the rayon is so far removed from bamboo due to the viscose process that the two materials are completely different. At present, there is a push for using viscose processing where eucalyptus is used as a source fibre

Currently, there are multiple ways to make rayon but the most common and considered the least “eco-friendly” is the viscose process.   Sustainability concerns often arise in the disposal of untreated effluent -  sodium hydroxide, Also, carbon disulfide and sulfuric acid are some harmful waste products.  Not all viscose producers have improper effluent disposal but the process inherently discharges a large amount of effluent so the chances of improper disposal greatly increases in markets with weak regulatory control. Further, the cost of treating the effluent is relatively high in the viscose process. 

A Greener Face for Viscose?

In India the viscose fabric was initially expected to be a replacement for cotton. The market began to develop heavily in the 1970s when there was an acute shortage of cotton. The Government of India made it obligatory that at least 10% of Viscose fabric should be blended with cotton. Since then, the demand for Viscose has increased and transformed year after year due to its attributes including its high absorbency and versatility. 

Recently, the United States, Europe and Japan have successively withdrawn from the viscose fiber market due to high labour costs and environmental protection laws. Meanwhile, Asian markets like China and India have had periods of accelerated development of viscose fiber. In 2013, the global viscose fiber market output grew up more than 13% to produce 4.9 million tons. The demand for viscose fabric shows no signs of decreasing so the question becomes how we can reduce the resource consumption and effluent waste. 

One textile manufacturing company,Pratibha Syntex has innovated the process through the use of spun dyed viscose fibres. Pratibha Syntex  reports that the new process bypasses the fabric dyeing process leading to 85% savings in water and 35% less energy usage. The company states the resultant fabric properties are better than a conventionally produced fabric and this the new fabric enables bright colours with better fastness, low pilling and excellent drape. 

Dhawal Mane, Assistant Manager of Sustainable Initiatives for Pratibha Syntex, states “It is important for a manufacturing setup like ours to innovate products that address issues which affect our stakeholders the most. Our product has the potential to bring a sizeable positive impact in the sustainability of our operations.”

While environmental impact in textiles often focuses on human toxicity and acidification, it is important to pursue a balanced approach as overall water usage is a concern in a water scarce regions in India. With consumer fibre preferences increasingly leaning towards man-made fibres, it has become important for companies to address resource challenges through innovation. Pratibha Syntex, known for their production of organic cotton fabrics, sees this as a strategically sustainable step.

The problem of chemical pollution in the pulp and viscose processing needs to be analysed carefully for the viscose-processed fabric to be considered sustainable. Due to the variety in chemicals used in process,  the cost of effluent treatment for wet processing will remain high.  

Pratibha Syntex’s water usage innovation could have a large impact on the sustainability concerns associated with viscose dyeing, if substantiated with the LCA assessment over the next several months. It is imperative that the Indian viscose industry addresses chemical pollution with effluent treatment and ensure the sustainability of viscose processing.