Sources of cellulose fibre & cellulose source

Sources of cellulose fibre  

 In the complex designs and structure of the plants, nature has used fibres as the basis of strength providing skeleton. Bundles of fibres bound together by natural gums or resins run through the roots, stems, fruits and leaves of plants. These strands of fibres are associated with varying amounts of other natural substances such as lignin, pectin, hemicelluloses, gums, waxes and colouring matters. The total carbohydrate material is usually designated as holocellulose. The amount of these associated substances 8 and the ease with which fibres can be separated from them determine the utility of the fibre as textile material: These fibres can be classified by its reference to the part of the plant from which they belong. The important sources of cellulosic fibres are mentioned below:

Seed fibre

The seed hairs like cotton contains cellulose with very less non- cellulosic substances ( 4-12 % ) .This makes purification most simpler than for most of other cellulosic fibres. Other seed fibres are kapok and bombax cotton .These fibres contain 55-65 % cellulose

Bast fibre

The bast fibres are long fibres of the outer bark of various plants which strengthen the stem of the plant. They include flax, hemp, jute, ramie, kenaf, sunn etc. The fibres are integrated with natural gum in the plant structure. The fibres are separated by removal of the gums and the process is generally known as retting

  Leaf fibre

Many of the cellulosic fibres like sisal hemp, Manila hemp are also obtained from the leaves of the plants. The fibres extend longitudinally the
full-length of the leaf and contribute strength to the leaves. The fibres are buried in tissues of the leaves and can be separated from the tissue by scrapping since there is no bonding between the fibre and the tissue. This process is known as 'decortications.

Fruit fibre

The husks of Coconut , betelnut and palmnut which protect the fruit for development can be processed and utilized as fibres. After removaľ'of the fruit, the husk can be extracted, retted and processed.

Source of cellulose 

Cellulose also occurs in many materials as non-fibrous form. The substances containing cellulose are as follows

wood

Wood is the most widely used cellulose material. It is found all over the world. Generally there are two types of wood:

(1) Hard wood and

(2) Soft wood.

The hard woods are composed of closely packed cells with thick walls. On the other hand, the soft wood are usually composed of large cells with thin walls. Woods are mainly cellulose, lignin and hemicellulose. There are three main chemical processes by which cellulose can be extracted from the wood. Those are:

(a) The sulphite process,

(b) The sulphate process and

(c) The soda process.

The soda process is generally used for hard woods

Grass

Another important source of cellulose is grasses and straw. Sabai grass, espato grass, cereal straw, rice straw and wheat straw etc are the main sources of cellulose.

Agriculture Wastes

Cellulose is the major constituent of the cell wall of plant life. So the residual wastes from utilized plants form a huge potential source of cellulose. The crushed stalk of sugar cane, corm cubs, rice halls, grains and seed hulls, soybean stems, sunflower stalks, castor bean stalks, nut shells etc are considered as sources of cellulose

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Cellulose from non vegetable source

 Cellulose is also found in animal and mineral kingdom. It occurs in fossil Woods, peat, lignite, mineral cellulose (sapperite) and animal cellulose like tunicin.