Fibres, Yarns and Fabric Construction
What this domain tests
The exam checks whether you can classify fibres, explain how fibre properties pass into yarns and fabrics, and recognise basic fabric structures. Expect label-reading, property-matching and simple fault diagnosis.
Core rules
- Fibres are natural (cotton, linen, wool, silk) or man-made (regenerated viscose; synthetic polyester, nylon, acrylic).
- Cellulosic fibres absorb water, conduct heat and burn like paper; protein fibres absorb less, felt with heat and friction, and smell like burnt hair.
- Staple fibres are short and twisted into yarn; filament fibres are long and may need little twist. More twist gives a stronger, harder yarn; low twist gives a softer yarn.
- Weaving crosses warp (lengthwise) and weft (widthwise). Plain weave is firm and balanced; twill shows diagonal ribs and drapes well; satin floats give shine but snag. Knitting interlocks loops, so it stretches; nonwoven fibres are bonded, not yarn-interlaced.
Worked example
A label says 100% polyester. A candidate must explain why a school shirt in this fabric dries quickly but feels warm. Polyester is synthetic, hydrophobic and thermoplastic: it absorbs little water, so drying is fast; low moisture regain and poor heat conduction can make it feel clammy or warm. It is strong and wrinkle-resistant but may hold oil stains and melt under a hot iron. The reasoning links fibre chemistry to care, not just the name.
Traps
Do not say “cotton is a fabric” when it is a fibre; do not confuse warp with weft; do not claim all man-made fibres are synthetic (viscose is regenerated); do not assume “strong” means abrasion-resistant. Check whether a property belongs to fibre, yarn or fabric.