Question
What is the difference between natural and synthetic fibres? Give three examples of each and explain how cotton fabric is made from cotton plants.
(CBSE Class 6 Science)
Solution — Step by Step
These come directly from nature:
| Fibre | Source | Used for |
|---|---|---|
| Cotton | Cotton plant (fruit) | Clothes, bedsheets |
| Jute | Jute plant (stem) | Bags, ropes |
| Silk | Silkworm (cocoon) | Sarees, scarves |
| Wool | Sheep (hair) | Sweaters, shawls |
These are manufactured by humans using chemical processes:
| Fibre | Made from | Used for |
|---|---|---|
| Nylon | Coal, water, air | Ropes, toothbrush bristles |
| Polyester | Petroleum products | Clothes, bottles (PET) |
| Rayon | Wood pulp (semi-synthetic) | Dress material, curtains |
| Acrylic | Petroleum | Blankets, winter wear |
- Picking: Cotton bolls (fluffy white balls) are picked from cotton plants
- Ginning: Seeds are separated from cotton fibres using a ginning machine
- Spinning: Fibres are twisted together to make strong yarn (thread)
- Weaving or knitting: Yarn is interlaced on a loom to make fabric
The key idea: fibres are thin strands, yarn is made by twisting fibres, and fabric is made by weaving yarn.
Fibre Classification Tree
flowchart TD
A["Fibres"] --> B["Natural fibres"]
A --> C["Synthetic fibres"]
B --> D["Plant fibres"]
B --> E["Animal fibres"]
D --> D1["Cotton — from fruit"]
D --> D2["Jute — from stem"]
D --> D3["Coir — from coconut husk"]
E --> E1["Silk — from silkworm cocoon"]
E --> E2["Wool — from sheep hair"]
C --> C1["Nylon"]
C --> C2["Polyester"]
C --> C3["Acrylic"]
C --> C4["Rayon — semi-synthetic"]Why This Works
Fibres are the building blocks of all fabrics. Natural fibres have been used for thousands of years — cotton was grown in India over 5,000 years ago. Synthetic fibres were invented because natural fibres have limitations (wool shrinks, cotton wrinkles, silk is expensive).
Synthetic fibres are stronger, cheaper, and dry faster. But natural fibres are more comfortable to wear in hot weather because they absorb sweat, while synthetics do not.
Common Mistake
Rayon confuses many students. It is made from natural wood pulp BUT processed in a factory using chemicals. So it is called a semi-synthetic fibre — not fully natural, not fully synthetic. In exams, if asked “Is rayon natural or synthetic?”, the correct answer is semi-synthetic (or “regenerated fibre”).