Source of Fibres
Senior 1 · Home Science
Source of Fibres
Lesson 1 of 4
18 min
Fibres are all around a Rwandan home, not only in clothes. The door mat may be sisal, the maize is stored in a woven plastic sack, the blanket may be wool or acrylic, the ceiling may hide a layer of glass wool, and an old kitchen roof may still be made of asbestos sheets. Each fibre came from a different source, and its source decides how it behaves: whether it soaks up water, keeps you warm, burns, melts or harms your lungs.
This lesson gives you the full family tree of fibres and the words used to describe how any fibre behaves. The next three lessons look at each branch in turn.
A fibre is a fine, flexible strand that is many times longer than it is wide. Fibres are the raw material of textiles, ropes, mats, paper and many building materials. Short fibres, measured in centimetres, are called staple fibres; very long, continuous fibres are called filaments.
Every fibre belongs to one of two families, and each family has three branches.
The characteristics (or properties) of a fibre are the ways it behaves. The main ones are:
| Characteristic | Question it answers |
|---|---|
| Length and fineness | Is it staple or filament? Is it thick or very fine? |
| Strength | How hard can you pull it before it breaks, dry and wet? |
| Elasticity | Does it stretch and then go back to its length? |
| Resilience | Does it spring back after crushing, or does it crease? |
| Absorbency | Does it soak up water and sweat? |
| Warmth | Does it trap air and hold in body heat? |
| Lustre | Is it shiny or dull? |
| Reaction to heat and flame | Does it scorch, burn, melt, or not burn at all? |
| Resistance | Is it damaged by insects, mould, sunlight or chemicals? |
Ishimwe lists fibre items she finds at home and at school, and places each one in the family tree.
| Item | Fibre | Family and branch |
|---|---|---|
| Door mat | sisal | natural, plant |
| Craft card decorated with dried banana fibre | banana | natural, plant |
| Warm blanket | wool | natural, animal |
| Old roofing sheet on a store | asbestos | natural, mineral |
| Shiny jacket lining | acetate | man-made, regenerated |
| Woven sack of maize | polypropylene | man-made, synthetic |
| Stretchy sports tights | nylon with elastane | man-made, synthetic |
| Ceiling insulation | glass wool | man-made, inorganic |
Using the table. Only the wool is likely to be attacked by moths, because it is protein. The sack and the tights will melt if they touch a hot charcoal stove, because they are synthetic. The asbestos and glass fibres will not burn, which is exactly why they were used in roofs and insulation.
Tip
Memory hook: "Plants, Animals, Minerals; Regenerated, Synthetic, Inorganic." Two families, three branches each. In an exam, name the family AND the branch, then give one characteristic that follows from the source.
Name the two families of fibres and the three branches of each.
Solution. Natural: plant, animal and mineral. Man-made: regenerated, synthetic and inorganic.
What is the difference between a staple fibre and a filament?
Solution. A staple fibre is short, measured in centimetres, like cotton or wool. A filament is very long and continuous, like silk or most man-made fibres.
A T-shirt label says "bamboo viscose". Is it a natural or a man-made fibre? Explain.
Solution. Man-made, regenerated. The bamboo is only the raw material: its pulp is dissolved in chemicals and re-formed into new viscose fibres in a factory.
Which characteristic is being described: (a) a shirt that comes out of a bag full of creases; (b) a towel that dries your hands well; (c) a satin ribbon that shines?
Solution. (a) Low resilience (it creases). (b) High absorbency. (c) Lustre.
Remember
Sources and credits
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
