Whither Cellulosics?

By Calvin Woodings, CWC Ltd

Introduction

The development of man-made fibres is one of the great industrial successes of the 20 th century. After 50 years of explosive growth in rayon technology, synthetic fibres now dominate the market. Cotton, for centuries the most important of all cellulosics is now taking second place to polyester. The other natural fibres and rayon appear relegated to little more than niches in a global textile market driven by the ready availability of cheap fossil fuels and the demand for commodity textiles.

Is the relative decline in use of biopolymers such as cellulose in textiles just another, if long-enduring example, of the last stage of the inevitable growth/maturity/decline life-cycle of most markets? Or is there any suggestion that, on a longer time scale, biopolymers will prove to be a serious rival for the synthetics?

This paper reviews how cellulosics arrived at their current position in the fibres market and examines possible futures.

Present Positioning

Graph 1 illustrates the major share changes over the last century.

Roughly half of the 45 million tonnes of fibre consumed annually are now made from polymers synthesised from fossil fuels. The only perturbations in this impressively smooth growth curve appear in the 73-74 period, the 78-84 period and the 90-91 period.

Pricing

Graph 2 brings together fibre, oil and pulp prices from a variety of sources to throw some light on the competitive positioning of the key fibres in the period from 1970. They are not all on the same basis and US figures are used in preference to less complete and more volatile European data.

They nevertheless illustrate the following:

  • A doubling of oil price due to the oil embargo during the 1973 Yom Kippur War.
  • The oil price controls during the Iranian Revolution/Iran-Iraq War in the 1978-82 period cause a massive disturbance in oil-price.
  • Return to "normal" oil pricing interrupted by the Gulf War in 1990.
  • Cotton increased from the 20c/lb to the 60 c/lb region during the 1970's removing it's traditional large price advantage over polyester.
  • Ignoring the effects of politics on oil-price, the oil-pulp price gap is increasing.
  • A quadrupling of oil-price over a ten year period hardly affected the price of polyester c.f cotton and rayon.
  • Polyester and cotton prices appear to be broadly similar and following the same trends over the last 30 years.
  • Rayon prices remain broadly in line with polyester and cotton until 1989 when they move rapidly ahead of both the competitive fibres and the price expectation based on pulp prices. (A graph of European prices would show the rayon premium to be even greater)
  • Lyocell, introduced at a premium price in 1990 increases in price until the capacity doublings occur in 1995 and 1998.

 

Graph 3 plots some of the key ratios using the data from Graph 2.

Aesthetic and Technical Considerations

The aesthetic, absorbency and comfort advantages still enjoyed by the biopolymer fibres has unquestionably slowed synthetic penetration of the apparel sector. Synthetics are used mainly for their low-cost, easy-care and durability characteristics. In the absence of fibres combining all these properties, polyester/cellulosic blends have been a most popular combination. Ratios varying between 35% cellulosic and 35% synthetic depending on the market positioning of the fabric and the relative prices of the fibres are typical.

Within the cellulosic part of the blend, rayon has to compete with cotton and can do this only:

  • a) When rayon prices (esp. modal or polynosic) are below cotton prices.
  • b) When a fashion in a particular sector values the softness, leaness and drape of rayon above the crisper, fuller, stiffer handle of cotton.
  • c) When the enhanced absorbency, uniformity and processability of rayon (in this case over bleached cotton at a higher price) is technically desirable, for instance in disposable nonwovens.

 

Synthetic Success

The enormous expansion of the synthetics in the 60's and 70's put the viscose rayon industry on the defensive. By 1973, despite having taken almost 25% of the 14 million ton cellulosics market without ever promoting the fibre strongly against "King Cotton", the future of man-made fibres was widely held to be synthetic. The viscose industry had entered an end-game strategy, its profits, still substantial during the upside of the textile cycle, being invested in synthetic fibres or in diversification ventures. A progressive tightening of the regulations governing the release of gaseous and liquid effluents from the viscose process compounded the problems. By the end of the seventies nobody expected to see a new viscose plant being built anywhere. In the absence of substantial reinvestment to reduce manufacturing costs, repositioning viscose rayon as a premium priced fibre for the more lucrative market niches became vital to survival.

Lyocell development

The lyocell process, developed through the 80's, offered an environmentally acceptable way of converting natural cellulose into a premium quality rayon fibre with tensile properties approaching those of polyester. Furthermore the technology offered the potential for converting pulp to fibre on a scale and at a cost to give polyester and cotton some serious competition. The high costs of developing the process and building the first plant came largely from the cash generated by the repositioned viscose process, but with lyocell seen as a long-term replacement for viscose, this was in effect, a major reinvestment in the rayon process.

The high levels of investment in the first plants necessitated launching the fibre at a premium price and therefore into the quality fashion-apparel market. This proved highly successful and led to rapid expansion up to the current capacity of around 100,000 tonnes. However this represents about one half of one percent of the current cellulosic fibres market, and lyocell fibre is still only available from two sources, Acordis and Lenzing.

At the time of writing, demand for lyocell has yet to increase to absorb the latest expansions and some repositioning of the fibre in the market will be necessary. The general softening of the world fibre market as exemplified by the steep declines in cotton and polyester prices (Graph 2) is a key element in the lower than anticipated demand for lyocell.

Possible Futures

One of the most thorough recent expositions of the outlook for cellulosic fibres was compiled by T F N Johnson of Courtaulds 1. He argued that continued population growth and increased per capita fibre use will result in a demand for a further 70 million tonnes of fibres by 2050. With the potential for further cotton yield or hectarage increases now limited, and with the synthetics still looking unlikely to provide the comfort element of future textiles, Johnson postulates a "Cellulosics Gap" of up to 20 million tonnes.

He points out that for 60 years, cotton production has grown almost entirely due to increased fibre yield per hectare. Land area under cotton cultivation has been constant for that period, and pressure for the same top quality agricultural land will increase due to the need to feed increased population. Better irrigation, higher pesticide use, higher chemical fertiliser use and genetic improvements achieved the cotton yield increase. In fact cotton cultivation in Russia became so intensive that despite its benign environmental image it has been the origin of environmental degradation on a massive scale 2. In the 1980's, a tonne of Central Asian cotton required approximately 800 kgs of fertilisers, 100 kgs of pesticides and an aggregate of 1.5 metres depth of water per square metre of growing area. In recent years cotton yield per acre has peaked and now appears to be unlikely to increase further in the foreseeable future.

1 "World Fibre Demand 1890-2050 by Main Fibre Type." T F N Johnson, Courtaulds Fibres UK, presented to the Chinese National Textile Council, 1997.

2 "Poisoned Waters", New Scientist 21 October 1995.

It is taken for granted that the implied need for an additional 50 million tonnes of synthetics will be readily provided.

The Comfort Gap

In reality a "comfort" gap of 20 million tonnes is likely to be filled by a combination of a variety of technologies:

  • • Development of equally comfortable blends containing progressively less cellulose.
  • • Some increased yield of cotton per hectare from genetic engineering advances yet to be achieved.
  • • Some increased use of prime agricultural land for cotton growing.
  • • Development of low-cost viscose and lyocell fibres.
  • • Development of soft flax fibres encouraged by agricultural subsidies and improved fibre separation methods.
  • • Development of truly hydrophilic synthetics.
  • • The use of wood-fibre in textiles.

 

The Role of Man Made Cellulosics

In order to realise the opportunity offered by Johnson's Gap, or even a gap of a tenth of that size, man-made cellulosics must rapidly close that other gap, the price differential with polyester. They must do it in such a way that financial community can conclude that investment in man-made cellulosics is at least as good an investment in more synthetics. The technology to achieve this has existed for some time, but the justification for the necessary long-term investment is hard to sell.

Consider the following:

  • • Rayon producers still regard the other rayon producers as their main competition.
  • • Cotton is the main competition for rayon, and cotton is still regarded as the invulnerable giant against which rayon cannot possibly be marketed.
  • • Polyester is clearly the main competitor for cellulosics but has now achieved economies of scale that the rayon industry has to emulate.
  • • Polyester prices are likely to return to the trend line from the unusually depressed levels of the last year.
  • • At today's prices, 75 to 80 cents/lb would then be the price level at which rayon would be a credible growth fibre.
  • • Existing rayon plants are unlikely to be viable at such prices if dissolving pulp remains at current price levels.
  • • Rayon plants could be built on the same scale as recent polyester staple plants (300,000-350,000 tonnes/year). On this scale their economics would be challengingly close to the target level.
  • • Lyocell has the potential to break out of rayon's long standing need for high quality dissolving pulp.
  • • A 350,000 tonne lyocell plant linked to a major source of low-cost/low grade dissolving pulp and using a modified process to make fibre with tensiles no better than current viscose rayon could well be viable.
  • • Such a plant would be a more than adequate demonstration that the Johnson Gap could be filled with highly profitable man-made cellulosics.

 

June 1999

Calvin Woodings Consulting Ltd

The Lodge, Eathorpe,

Warwickshire

CV33 9DF

UK

Tel: +44 (0) 1926 633 522

Fax: +44 (0) 1926 633 522

Email: CW@Nonwoven.Co.UK