Page 20 - Curriculum Visions Dynamic Book

(Above and below) Cotton is the fibre enclosing the cotton seed. The pod containing the cotton filaments and seeds is called a cotton boll.
Boll fibre
The fibres from seed cases, or bolls, of plants
are the finest in a plant. They are also free from the many impurities found in leaf and stem fibres. Boll fibres include kapok and cotton. They are made of single long cells and are not stuck together with natural gums.
Boll fibres are among the most valuable of fibres for high-quality fabrics. They are also used in some high-quality papers.
Bast fibre
The fibres of the stems of plants – called bast fibres – are the most widely used plant fibres. They are softer and more flexible fibres than leaf fibres, although not as fine as boll fibres.
The plants most widely used for their stem fibres are those flowering plants with net-veined leaves. The most important fibres from this group are flax, hemp, and jute.
The fibres can be metres long and made of overlapping cells bound into bundles by natural gum. The fibres are found between the bark and the woody core of the plant.
To recover the fibres, the plants are cut and then beaten or peeled. The fibre bundles are called strands.
Bast fibres are strong and more
pliable than leaf strands and so are preferred for ropes, coarser sacks, and some heavy-duty fabrics. Flax is the raw material for linen.
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