Textile Fiber Microscopy

2Animal Fibers

2.1 Wool

Wool is an ancient fiber and one of the earliest fibers to be spun into yarn. Wool comes from the hair of sheep, probably the first animal to be domesticated [1]. The fleece of a wild sheep, or primitive sheep, prior to being domesticated, consisted of a long outercoat (kemp) and a light downy undercoat. The fleece of today's sheep is mainly the soft undercoat [1]. Although kemp fibers still exist in various breeds of sheep, different wool types have been developed without the kemp fibers, such as the Merino wool (which will be discussed later).

Wool is a fiber with many valuable properties, and when combined, no other synthetic fiber is their equal. These include good moisture absorption, the ability to be shaped by heat and moisture, excellent heat retention, feltability, and flame retardancy [1].

Wool is not simply hydrophilic, similar to many plant fibers, nor hydrophobic, like many synthetic fibers. Wool fibers have tiny scales on their surface adding a new dimension to the properties of wool. The scales do not allow water droplets to enter the fiber as they repel water while still absorbing water vapor. Thus, wool fibers absorb moisture without feeling wet. This type of fiber, called hydroscopic, is the reason why protein fibers are comfortable to wear [1]. The most recognizable part of wool fibers are its scales on the outside of the fiber. These scales have their own particular functions; among them is the scales' ability not only to repel water but ...