Textiles and Clothing
This domain tests fibre classification and properties, yarn and fabric construction, common finishes, and the care and selection of fabrics.
Fibres
- Natural: cellulosic - cotton, linen, jute; protein - wool, silk.
- Man-made: regenerated - rayon, acetate; synthetic - polyester, nylon, acrylic.
- Properties follow chemistry: cotton absorbs well and tolerates alkali but burns like paper; wool and silk are proteins, damaged by strong alkali and chlorine bleach, and smell of burning hair; polyester is thermoplastic, low-absorbency, oleophilic and quick-drying.
Yarn and fabric
- Spinning turns fibres into yarn; twist adds strength; staple fibres are short, filament fibres long.
- Weaving uses warp (lengthwise, stronger, more twist) and weft. Basic weaves: plain (even, durable), twill (diagonal rib, strong), satin (lustrous, floats, snags easily).
- Knitting interlocks loops - stretchy and porous but prone to runs; non-woven and felt fabrics have no grain and poor drape.
Finishes and colour
Singeing, desizing, bleaching, mercerisation (cotton - more lustre, strength and dye uptake), calendering, sanforisation (shrinkage control), water-repellent and flame-retardant finishes. Dyeing colours the whole fabric; printing applies colour to one side in a pattern.
Worked example
A woollen shawl shrank and matted after a hot machine wash with ordinary detergent. Reason: wool scales felt under heat, moisture and agitation, and alkaline detergent plus wringing damages the protein fibre. Correction: cool water with neutral wool detergent, no rubbing or wringing, dry flat in shade, no chlorine bleach, warm iron only.
Traps
- Calling rayon synthetic - it is regenerated cellulose.
- Claiming polyester absorbs sweat well.
- Using hot water on a blood stain, which coagulates protein; use cold water.
- Reversing warp and weft.