Page 53 - Advances in Textile Biotechnology

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Developments in processes and equipment for
enzymatic textile treatments

M. M. C. G. WARMOESKERKEN and G. H. BOUWHUIS,
University of Twente, The Netherlands

Abstract: The role of mechanical energy in enzymatic textile treatment is
examined. The special properties and behaviour of enzyme molecules
can cause poor performance on an industrial scale owing to the absence

of liquid flow in the capillary pores of textile. The role of mass transfer
in these systems is discussed, a squeezing factor α is introduced and a
model is derived with which the mass transfer rate in textile materials
can be calculated. The phenomenon of exhaustion of the capillary liquid
during the adsorption of the enzymes is also discussed. A dynamic
adsorption model is used to explain this phenomenon.

Key words: mass transfer, textile processing, enzymatic treatment.

2.1 Introduction
The application of enzymes in textile treatment processes seems to be quite
simple at first sight: just replace the traditional chemicals by enzymes.

However, in practice, it was found that such an approach results in poor
performance often leading to a reluctance to use modern enzyme technol-
ogy in textile treatment processes (Bouwhuis et al. 2009). Because enzyme
molecules are much bigger than the traditional chemical molecules such as
sodium hydroxide, enzymatic treatment processes are often diffusion con-
trolled, Nierstrasz and Warmoeskerken (2003). Moreover, the kinetics of
enzymatic reactions is more complex than for traditional chemistry. This
complex diffusion control of the transport of enzymes inside the pores of
a fabric leads to a suboptimal adsorption of enzymes at the capillary surface.
Therefore, the key for a good performance using enzymes in textile treat-
ment processes is an optimal mechanical energy to prevent diffusion control.
It could be argued that the enzyme amylase is successfully applied in the
textile industry for the desizing process without transport limitations, but
the reason for this is that the size is present only at the outer surface of the
weft yarns and these surfaces can easily be accessed by enzymes without a
limiting transfer process between the fibres of the yarns.

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