[Chemistry Class Notes] on Animal Fibre Pdf for Exam

Animal fibres are naturally occurring fibres that are sourced from animals, as the name suggests. Animal fibres are made up of different types of proteins in general. Some of the most common animal fibres are wool and silk. You must know that all animal fibres are extracted from different animals and hence have different properties from one another. Also, the kind of fibres depends from one animal to another. 

Consider, for example, both Merino and Cotswold are two different kinds of wool that are extracted from different species of sheep. Merino is known for its softer texture, whereas Cotswold is known for its coarse texture. You must also know that the natural fibres from animals tend to vary in consistency than the synthetic fibres. The synthetic ones are more uniform. We will learn today about what animal fibres are, the difference between animal fibres and plant fibres, and the different types of animal fibres.

Names of Animal Fibres

The fibres obtained from animals are generally textile. These fibres are generally produced from the animal’s fur, skin, hair, or even secretion in the case of the silkworm. Once these animal fibres are extracted they are generally knitted or woven for forming beautiful animal fabrics. If you have to name two fibres obtained from animals, they can be silk and wool. 

However, if you consider historically, these animal fibres have been employed for manufacturing warm and soft jackets, shawls, blazers, coats, ponchos, and several other forms of clothes and accessories. If you have to name any two animal fibres applications that are rougher, they are usually covers, carpets and rugs.

Difference Between Animal Fibres and Plant Fibres

Types of Animal Fibres

If we have to name two animal fibres that are widely used, they are wool and silk. Let us now learn about the types of animal fibres in detail.

1. Wool

Wool is an animal fibre derived from different animal furs which belong to the Caprinae family. We usually relate wool to sheep, however, wool can also be derived from other animals like goats, rabbits, and alpacas. Different kinds of wool from different animals have different properties from one another. The main difference between the wool and hair of sheep is that the wool of the sheep consists of scales which overlap in the same manner as the shingles on a roof. Many kinds of wools are also known to possess more than 20 kinds of such bends in just one inch. However, the diameter of one strand of the wool ranges from 17micrometres to about 35 micrometres.

Let us discuss about the feature of those different types of wool fibres – 

1. Angora wool, the rabbit hairs obtained from a special species of rabbits named as Angora rabbit. The fur of the angora rabbits are considered to be extremely soft and pleasant to touch, thus due to its desirable characteristics are in a very high demand. It is often mixed with other types of wool to add warmth and softness in the final product.

2. Alpaca fibre: this is obtained from one of the South American camelid mammal species, by the same name Alpaca. This wool is very light in comparison to the normal sheep fibre and not only that, it is warmer than the traditional sheep wool.

3. Wool obtained from the american bison, known as the bison wool, is also quite famous in the textile industry. 

4. One extremely famous type of wool goes by the name of Cashmere wool (derived from the word Kashmiri), and is processed from the fur of the Cashmere goat found in the Kashmir territory of India. This type of wool has a luxurious texture in it and is extremely soft and lightweight. Kashmir shawl (also spelled as Cashmere) created from the Cashmere wool is quite popular in the textile industries around the world.

5. Like rabbits, goats also have pieces with the name of angora goats, the fur of which is called the Mohair wool, this type of wool is considered very similar to silk. Mohair is famously known for its durability.

2. Silk

Silk is regarded as a naturally occurring protein fibre. It can also be woven into textiles in different ways. The most commonly known silk form is the which is obtained from the larvae of Bombyx mori species. Silk rearing is called sericulture. The degummed fibres which are obtained from Bombyx mori have a diameter which ranges from 5 – 10 m. There are different types of silk which are famous for their shiny appearance. This is because of the triangular prism-like and cross-sectional structure of these fibres. These prism-like fibrous structures tend to allow light which is incident to the silk fibres to refract at varying angles.

You must know that one whole silkworm cocoon produces one long fibre. Therefore, one should be careful while unwinding these fibres from the silkworm cocoons. Also, the quality of the silk fibres depends on how healthy the silkworm is. This, in turn, depends on the living conditions and the food which they are provided with.

Spider silk is amongst the most powerful naturally occurring fibres known to man. It is the strongest dragline silk which is believed to be about three times stronger than kevlar and more than five times tougher than steel. There are some types of spider silks that are known for their enhanced elasticity. The silk which is woven by the ogre-faced spider is considered to be stretchable more than five times its length without damaging itself!