textile science

2. Classification of textile fibers

Textile fibers are classified into two main classes

i.                    Natural fibers

ii.                  Manmade fibers

 

 

NATURAL FIBERS

They occur naturally and are extracted from natural resources/raw materials. They are further grouped into three classes;

i.                    Vegetable/plant / cellulosic

Plant fibers are composed of cellulose i.e. the structural material that gives strength to plants and therefore are classified as natural cellulosic fibers. Vegetable fibers are obtained from the following

a.       Leaves – sisal, manila, abaca

b.      Seeds – cotton, kapok

c.       Stem bast – flax, hemp, jute

d.      Fruits – coir

e.       Husk – coconut

The strands of cellulose fibers in the plants are associated with other natural materials such as lignin, wax, gum and pectin.

The cellulose fibers therefore have to be separated from other materials for it to be useful raw materials for textiles.

 

ii.                  Animal / protein fibers

 

Natural protein fibers are obtained from animal sources like hair and other secretion. Fibers include

a.       Covering from such animals as sheep, mohair goat, Cashmere goat, horse, rabbit and camel.

b.       Secretions are obtained from the larva, or worm stage, of the silkworm, which spins the cocoon from which silk fibers are obtained and from the spider which spins fine fibers in making its web.

There are some properties of hair fibers and secretions which are quite similar and on the other hand there are properties which are totally different.

There are two types of animal fibers

a.       Filament length – a continuous length from silk worm

b.      Stable length – short length e.g. Wool & hair obtained from the process of sheering

 

iii.                Mineral fibers

Fibers obtained from minerals e.g. Asbestos, they are of little significance but are used in specialized materials e.g. fine resistance fabrics.

MAN-MADE FIBERS / MACHINE MADE FIBERS

This are fibers that are made by chemical reactions. Classified into two groups;

i.                    Synthetic

These are textile fibers that are wholly produced from chemical substances. Synthesis (to build up). They are made by combining a chain of smaller molecule to five a larger molecule.

The large molecule is known as polymer and the process is known as polymerization e.g.

AIR + WATER + COAL + PETROLEUM = POLYMER

Example of synthetic fibers; polyester, nylon, acrylic, mod acrylic

ii.                  Regenerated fibers

This are reborn fibers gotten from natural materials, treated with chemicals to give filament fibers e.g. cotton linters & wood pulp treated with chemicals.

Examples of regenerated fibers.

a.       Viscos rayon

b.      Acetate rayon

c.       Tri-acetate