Textile Fibres, Yarns and Fabrics: Types, Properties and Identification
What this domain tests
Fibre classification, the link from fibre to yarn to fabric, and the standard identification tests - especially the burning test, which appears in almost every paper.
Classification and yarn basics
- Natural: cotton, linen (bast), silk (filament), wool (staple, scales).
- Man-made: regenerated (viscose, modal, lyocell) and synthetic (polyester, nylon, acrylic, elastane).
- Staple fibres are short and spun; filament fibres are continuous.
- Yarn count Ne = number of 840-yard hanks per pound; higher Ne means finer yarn. Twist is measured in turns per inch.
- Fabric structures: woven (plain, twill, satin), knitted (single jersey, rib, interlock), nonwoven.
Identification
- Cotton: burns like paper, grey soft ash, no bead, smells of burning paper.
- Polyester: melts and shrinks away, hard black bead, sweetish chemical smell.
- Silk and wool: smell of burning hair, crushable dark bead; wool is rougher and self-extinguishing.
- Nylon: melts, hard bead, celery-like odour.
- Confirm with feel, lustre, microscopy (cotton is a twisted ribbon, wool has scales) and solubility tests.
Worked example
A swatch is soft, melts into a hard black bead and glazes under a hot iron. Melt-and-bead points to a thermoplastic, so polyester or a polyester-rich blend. The correct answer is polyester, but a good answer adds that most market fabrics are blends and a burn test on a blended yarn shows mixed behaviour, so fibre-content labelling or a laboratory test is needed for certainty.
Traps that cost marks
- Equating shine with silk; viscose and polyester are also lustrous.
- Reading Ne backwards - a 60s count is finer than a 20s count.
- Assuming a burn test on a blend gives a clean single answer.
- Mixing up twill (diagonal wales) with satin (float-faced, lustrous).