Page 331 - Advances in Textile Biotechnology

13

Hydrolysis of regenerated cellulose fi bres for
textile and other applications

T. BECHTOLD and C. B. SCHIMPER, Leopold-Franzens
University Innsbruck, Austria

Abstract: The use of steaming, drying, and alkalisation as pretreatment
processes for regenerated cellulose – such as lyocell type fi bres, viscose
and modal fibres – is described. These processes overcome the problems

caused by the size of the enzymes and the average pore diameters of

regenerated cellulose fibres and allow cellulases to access the pores in

the fibres so that hydrolysis is not restricted to the surface of the fi bre.

An efficient combination of pre-treatment steps and cellulase hydrolysis

exhibits significant potential to produce new materials. Differences in
crystal structure between native cellulose fibres and mercerised cotton

and regenerated cellulose fibres are described and the factors that

determine the effects of cellulase on substrates are outlined.

Key words: cellulose fibres, textiles, cellulase, hydrolysis, alkalisation,
viscose, lyocell, modal.

13.1 Introduction
Cellulose is the most abundant polymer provided by nature. Fibrous struc-
tures can be easily separated from plant sources, e.g. seed (cotton) and stem

(flax, hemp, jute), or are available via dissolution/regeneration steps as
regenerated cellulose fibres, e.g. lyocell, viscose or modal fi bres. The ability

of cellulose polymers to interact with water by sorption in the polymer

structure, by swelling and uptake of liquid water into fibre pores explains
the favourable wear and comfort properties of textiles containing cellulose
fi bre.

In 2007, the share of man-made cellulose fibres of the total textile fi bre
production of 76.192 million tonnes per year can be estimated at 3.592
million tonnes, which corresponds to 4.7% (Anon., 2008). In the same year
an amount of 26.704 million tonnes of cotton was produced, which indicates

the relative size of the cellulose fibre market and demonstrates the substan-
tial potential of man-made cellulosics.
Owing to the limited farmland available for cultivation of cotton and
increasing concerns about environmental aspects of cotton farming such as
water consumption for irrigation and the use of pesticides and herbicides,

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