Page 124 - Handbook of Properties of Textile and Technical Fibres

Physical, chemical, and tensile 4

properties of cashmere, mohair,
alpaca, and other rare animal

fibers

Bruce A. McGregor
Deakin University, Geelong, VIC, Australia

4.1 Introduction

This chapter discusses animal fibers used in textiles other than the wool grown by
sheep. These fibers include cashmere, mohair, qiviut (musk ox), alpaca, llama, vicu~ na,
guanaco, Bactrian camel, yak, bison, and angora (rabbit), which are generally
acknowledged to have special properties of softness, smoothness, and lustre, when
compared with sheep wool. They also have other attributes that affect market and con-
sumer perceptions such as rarity and exotic sources of production. These fibers are
collectively known as luxury or specialty fibers. Their use in textiles began before
recorded history in a range of civilizations. In combination with wool, these rare an-
imal fibers extend the range of textiles and textile products available to consumers
and the fashion industry (Watkins and Buxton, 1992; Anonymous, 1997; McGregor,
2000a).
Like wool, these fibers are composed of a-keratin, with an outer surface of overlap-
ping cuticle cells. Collectively, the textiles composed of these fibers exhibit a large
range in fiber diameter. For example, vicu~ na has a diameter of 13e15 mm, cashmere
13e19 mm, alpaca 18e27 mm, and mohair 22e40 mm. For many of these fibers, the
raw greasy fleece contains impurity fibers that have medulla, which are essentially hol-
low cells in the centre of the fiber shaft. For many fibers the medullated fibers are
mostly coarse hairs that need to be removed during processing. Medullated fibers
diffract light differently in dyed textiles compared with solid fibers, thus providing a
distinctive visual effect but they are coarser and may provide undesirable prickle sen-
sations in garments. For some fibers, such as angora, the medullated fibers are a major
positive feature of the final textile, providing a soft fluffy appearance.
Scientific knowledge of these rare animal fibers is limited and research effort small
compared with research into wool and other natural and man-made fibers, although in
recent years this situation is changing. What information that is available is scattered,
in inaccessible publications, or often relates to single samples. The surface properties
of these rare animal fibers differ from that of wool and as a consequence, compared
with wool, are more difficult and costly to process. In particular, the need for additional
special processing to remove the coarse hair from cashmere, llama, yak and qiviut,

Handbook of Properties of Textile and Technical Fibres. https://doi.org/10.1016/B978-0-08-101272-7.00004-3
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