Textile Fibres
This domain tests fibre classification, the properties that decide fabric use, and simple identification tests.
Fibre classes
- Natural: vegetable/cellulosic (cotton, linen, jute), animal/protein (wool, silk), mineral (asbestos).
- Man-made: regenerated (viscose rayon, modal, lyocell) and synthetic (polyester, nylon, acrylic, spandex).
- Staple fibres are short and must be spun; filament fibres are continuous. Silk is the only natural filament.
Properties that drive choices
Cotton is absorbent, breathable, creases and shrinks. Linen is strong and cool but creases badly. Wool is warm, elastic and felts. Silk is lustrous and strong but sun-sensitive. Viscose is absorbent but weak when wet. Polyester is strong, quick-drying, thermoplastic and low-absorbency.
Identification
Burning test: cotton smells of burning paper and leaves grey ash; wool and silk smell of burning hair and leave a black crushable bead; polyester melts and forms a hard bead. Also use feel, lustre, microscopic appearance and chemical solubility.
Worked example
A swatch burns with a paper smell and leaves soft grey ash: it is cellulosic - cotton, linen or viscose. To separate them, check lustre and drape: viscose is lustrous and soft, linen has slubs and is stiff. Test one property at a time.
Traps
- Calling silk a staple fibre.
- Assuming all natural fibres are cellulosic; wool and silk are protein.
- Expecting polyester to scorch like cotton; it melts.
- Forgetting that blends give mixed burn results.