Surface Modification of Cellulose Acetate with Cutinase and ...

Subchapter 3.1
The cortex comprises the main bulk. Cortical cells are long, polyhedral, and spindle-
shaped and consist of intermediate filaments (microfibrils) embedded in a sulfur-rich
matrix.
Cuticle cells and cortical cells are separated by a continuous intercellular material, the
cell membrane complex, which is mainly composed of non-keratinous proteins and
lipids (Rippon, 1992; Makinson, 1979; Plowman, 2003; Negri et al., 1993).
The composition and morphology of the wool surface is primarily modified in fibre pretreatment
processes (Brack et al., 1999).
3. Conventional Finishing Processes for Wool Fibre
A variety of processes are available to improve the appearance, handle, performance
and durability of the wool fabrics. Such processes include scouring, carbonizing,
bleaching, dyeing, antimicrobial finishing and shrinkproofing.
3.1. Scouring
Raw wool contains 25-70% by mass of impurities. These consist of wool grease,
perspiration products, dirt and vegetable matter such as burrs and seeds (Rippon, 1992;
Pearson et al., 2004). Before the more specialised finishing processes are applied,
fabrics usually require cleaning (scouring) to remove these impurities (Pearson et al.,
2004; Lewis, 1992).
3.2. Carbonizing
If not completely degraded and removed from the textile goods, vegetable matter and
skin residues will lead to uneven dyeing and printing. The vegetable matter is normally
removed by carbonizing, a process where wool is impregnated with sulfuric acid and
then baked to char the cellulosic impurities. The residuals are then crushed and
extracted from the wool as carbon dust by brushing and suction.
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