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