Enzymatic Treatment of Fibers for Nonwovens

Abstract

Cellulases are natural catalysts for the modification of cellulosic materials. The major advantage of enzymes in wet processing is their specific action without undesirable side effects. Cellulase treatment is commonly used to produce specific finishing effects such as ageing, defuzzing, and softening. The latter is often achieved by sacrificing the strength of the fabric. The strength loss problems would be severe in case of nonwovens since cellulase could attack bonded area of the fabrics which leads to significant web strength loss. Therefore, this research was undertaken to investigate the effects of enzymatic pretreatment on the properties of cotton fibers and fabric produced from enzymatically modified fibers.

The first stage of this research was to investigate the effect of cellulase action on bleached cotton fibers. Two enzyme solutions, Cellusoft L, a commercial whole cellulase solution, and monocomponent endoglucanases (EG) devoid of its cellulose binding domain (CBD) were used in this work. Enzyme hydrolysis was monitored by weight loss, enzyme adsorption and reducing sugar formation. The effect of enzyme action on the fiber surface was also analyzed by Congo red dye analysis and imaging with Scanning electron microscope (SEM). The analysis revealed that Cellusoft L was more aggressive than the CBD-free monocomponent endoglucanases.

Based on the analysis of reducing ends, nonwoven fabrics were prepared by carding and hydroentangling of fibers treated under selected conditions. The fabrics prepared from fibers treated with Cellusoft L and CBD-free EG's, showed improved performance in terms of tenacity in comparison to fabrics prepared from untreated fibers. However, improved bending properties were observed with fabrics made of fibers pretreated with Cellusoft L rather than the fabrics made of CBD-free Endoglucanases treated fibers. It has been established that a soft and strong fabric was obtained if fibers were pretreated with cellulases before the formation of nonwoven fabric.