Textile Fibres and Fabric Identification
This domain tests fibre recognition by origin, burning behaviour, solubility and simple chemical tests, plus the care consequences of each result.
Core rules
- Natural fibres are cotton, linen, wool and silk. Common man-made fibres are viscose rayon, acetate, polyester, nylon, acrylic and elastane.
- Burning test: cotton and linen burn like paper, smell of burning paper and leave soft grey ash. Wool and silk smell of burnt hair and leave crushable black ash; wool burns more slowly and often self-extinguishes. Polyester and nylon melt, form a hard bead and give a chemical or sweetish smell. Acetate melts with a vinegar note.
- Solubility confirms the result. Acetate dissolves in acetone; polyester does not. Wool and silk are destroyed by sodium hypochlorite bleach; cotton is not.
- Blends show mixed burning behaviour, so a flame test alone cannot give a blend ratio.
Worked example
An unknown white fabric melts, pulls away from the flame, smells sweetish and leaves a hard black bead. It is thermoplastic, likely polyester. An acetone test gives no dissolution, so acetate is excluded. If it had dissolved, the answer would be acetate. Reasoning: a hard bead means melting, not paper ash, and acetone separates acetate from polyester.
Traps that cost marks
- Burning a blend and naming one fibre only.
- Confusing wool and silk: both smell of burnt hair, but silk leaves a softer, finer ash.
- Using chlorine bleach on wool or silk, which destroys them.
- Assuming synthetic always means polyester.