This is the last part of an article written at the time of the Lenzing take-over of Tencel and reviews the state of man-made cellulosic fibres at that time. Click here to go to the first part.
Birla Viscose: a new line and a new process dedicated to nonwovens (Continued from part 3)
One of the Thai production lines has been uprated to make a better fibre for the Western nonwoven markets and at the time of writing they are starting up a completely new 20,000 tonne/annum line dedicated to the same sector. This line is an addition to the 90,000 tonne/annum Indonesian plant and has been designed to use a unique zinc-free process developed by Birla Research at their HQ in
. Zinc became a key ingredient of viscose spin-bath chemistry back in the second decade of the 20th century to allow the production of stronger, more extensible fibres and has stayed there ever since. Birla correctly argued that zinc and the traces of other heavy metals which can accompany it in raw material form is not necessary for disposable nonwoven production. According to Shubkham Varshney, Birla’s Vice President of International Business, the zinc-free fibre as produced in Indonesia has a tenacity of 2.6 gms/denier with 20% extension (dry) and somewhat brighter appearance due to the C-shaped cross-section which emerges from the zinc-free system. This lustre may be undesirable in nonwovens so titania is used to kill it, but other cross-sectional effects such as increased softness and bulk remain apparent. Nagda, India
In addition to developing the new zinc-free process, Birla Research has now completed its new pilot line for modal fiber production and also claims to have their lyocell pilot line operating successfully.
New Plant in
Mr Varshney also revealed that Birla are exploring greenfield sites in China with a view to building a major new viscose plant, with a 30,000 tonne/annum output first phase. This would be the first line in China to be based on 100% imported wood pulp cellulose and hence be capable of much higher quality than the smaller Chinese plants which have been designed to use cotton-linter pulps. The fibre would be a quality product for export and for
China’s rapidly expanding hydroentangled nonwovens industry.
What does the future hold?
After decades of declining sales, the nonwovens-led turn-around in the fortunes of man-made cellulosics should continue. Global use of the fibres is likely to increase providing their price relative to cotton and polyester remains much the same as in the last year. Wet-wipe demand for cellulosics will continue to rise for several years yet, but if rayon prices increase too much the pressure to develop the harder to use cotton blends and harsher woodpulp wipe-blends will intensify.
If lyocell maintains its current relation to viscose price, it should continue to replace viscose in nonwovens. Now that the vast majority of lyocell is made by a single producer, customers will be watching these price ratios very carefully. Lenzing will bring much needed stability and long-range thinking to the combined lyocell operations, but they must resist the inclination to improve their returns too quickly. Consumers already argue that more lyocell capacity, ideally from another lyocell producer, is urgently needed. Maybe the prospects for the TITK/Zimmer technology finally getting into production with Baoding Swan in
China are increased by the merger. On the other hand, Lenzing are likely to be more aggressive than Acordis in defence of their lyocell patents, so licencing deals apart, the entry barrier for newcomers may now be higher than it used to be.
Finally, we should remember that relative to the other fibres, lyocell technology is in its infancy. Combined under Lenzing, “critical mass” has been achieved and it is more likely to get the R&D effort needed to allow second and third generation processes to emerge. These processes would allow the fibre specification and, crucially, process costs to be reduced to levels appropriate for nonwovens. They would even allow the development of microfibre spunlaid and “melt-blown” cellulosic nonwovens which when hydroentangled would provide a range of disposable fabrics the major converters can still only dream about.
Woodings C., Int. Text. Bull.,vol. 50, no. 4, Aug. 2004, pp 26-28 (P)
Click Here for the EU report on the proposed CVC takeover of Lenzing in 2001
 Corsadi comprised Tencel, Acetate Chemicals, Cordenka (industrial yarns) and Polyamide High Performance GmbH.
 “Zinc-Free Staple Fibre Process” by Jain and Gupta: World Textile Congress,
Huddersfield, July 1997. This process uses a small amount of aluminium instead of zinc.