1. Prepare a presentation on " Fibres from Animals "based on the information available on the Internet or in Literature.
Answers
Animal fibres are the natural fibres that can be sourced to animals. These fibres are usually made up of different kinds of proteins. The most popular examples of animal fibres include silk and wool. It is important to note that animal fibres that are extracted from different animals usually have different properties. Furthermore, the types of fibres may also vary from species to species. For example, both Cotswold and Merino are different types of wool (extracted from different sheep species). The former is known for its coarse texture whereas the latter is famous for its soft texture. It can also be noted that natural fibres vary in consistency whereas synthetic fibres are known to be more uniform.
The textile fibres that are derived from animals are usually animal fibres. Such fibres are usually produced from animal hair, animal fur, animal skin, or certain secretions (usually from insects such as the silkworm). Once extracted, animal fibres are usually woven or knitted (or sometimes felted) in order to form beautiful animal fabrics. Historically, animal fibres have been employed in the production of soft and warm jackets, wraps, blazers, shawls, ponchos, coats and other forms of clothing and accessories. Carpets, covers, and rugs are usually made of relatively rougher animal fibres.
Examples of Animal Fibres
Silk
Silk is regarded by many to be “natural” protein fibre. This animal fibre may be woven into textiles in certain ways. The most commonly known form of silk is the one that is obtained from the cocoons (that are produced in captivity) by the silkworm larvae of the Bombyx mori species. The practice of silk rearing is often referred to as sericulture. It can also be noted that the degummed fibres that are obtained from the Bombyx mori species are known to have a diameter ranging from 5 to 10 μm. Certain types of silk are famous for their shimmery appearance, which is usually a result of the triangular prism-like cross-sectional structure of the fibres. Such prism-like fibrous structures allow the light that is incident to the silk fibre to be refracted at different angles.
It is important to note that one entire silkworm cocoon yields one long fibre. Therefore, care must be taken whilst unwinding the fibres from the silkworm cocoons. Furthermore, the quality of the silk fibres also depends on the healthiness of the silkworm larvae which, in turn, is dependent on the food and the living conditions they are provided with.
One of the most powerful natural fibres known to man is spider silk. In fact, the strongest dragline silk known to man is believed to be over three times tougher than kevlar and over five times stronger than steel. Certain types of spider silk are also known for their elasticity. For example, the silk that is woven by the ogre-faced spider is known to have the ability to stretch to over five times its length without sustaining damage.
Wool
The term ‘Wool’ is generally used to refer to the animal fibres that are derived from the furs of animals that belong to the Caprinae family. Although wool can be usually sourced to sheep fur, it is not uncommon for wool to be harvested from other animals such as rabbits, goats, and alpacas. The primary difference between sheeps wool and hair is that sheep’s wool is known to contain scales that tend to overlap (in a manner similar to shingles on a roof). In fact, some types of wool are known to have over 20 such bends in a single inch. The diameter of a strand of wool can range from 17 micrometres to around 35 micrometres.