Fibre properties and shapes
A fibre is a fine hair-like strand. Fibres are natural (from plants or animals) or manufactured (regenerated from wood pulp, or synthetic from oil).
| Fibre | Shape | What it gives |
|---|---|---|
| Cotton | Flat, twisted ribbon | Soft, absorbs water, cool, creases easily |
| Wool | Wavy (crimped) with scales | Traps air so it is warm; can felt and shrink |
| Silk | Smooth, triangular | Shiny, smooth, strong for its weight |
| Polyester | Smooth rod (shape can be engineered) | Strong, dries fast, resists creases, not very absorbent |
| Elastane | Long chains that spring back | Very stretchy |
Key performance properties: strength, elasticity, absorbency, warmth, durability, flammability, crease resistance and how easy it is to care for.
Spinning fibres into yarns
A yarn is a long continuous strand made from fibres. Short fibres (staple fibres such as cotton and wool) are cleaned, combed straight (carded), drawn out and then twisted. Long filament fibres (silk, most synthetics) can be used almost directly, sometimes textured to make them bulky.
- Low twist: soft, bulky, weaker yarn (knitting wool).
- High twist: strong, smooth, firm yarn (sewing thread).
- Plied yarn: two or more yarns twisted together for extra strength.
- Fancy yarns: loops or slubs for texture.
Blends and mixtures
No single fibre is perfect, so designers combine them.
- Blend: two or more fibres spun together into one yarn, e.g. 65% polyester / 35% cotton.
- Mixture: different yarns used in one fabric, e.g. cotton warp with a wool weft.
Reasons: improve performance (strength, stretch, fewer creases), cut cost, change look and feel, and make care easier. Example: adding 3–5% elastane to cotton gives jeans that stretch and recover.
Woven, knitted and non-woven fabric
Woven
Two sets of yarns cross at right angles on a loom. Warp yarns run along the length; weft yarns go across. The finished edge is the selvedge. Woven fabrics are stable, strong and fray at cut edges.
- Plain weave: over one, under one (cotton shirting, calico).
- Twill: over two, under two, shifting each row to make a diagonal line (denim). Strong and hard-wearing.
- Satin: long floats over many yarns give a smooth, shiny surface but can snag.
Knitted
Loops of yarn link together. Weft knit: one yarn runs across in rows (T-shirts, jumpers); it stretches a lot and can ladder. Warp knit: many yarns loop along the length (sportswear, net); more stable and does not ladder.
Non-woven
Fibres are made into a web and joined by bonding (heat, adhesive or needle-punching) or felting (wool fibres locked by heat, moisture and rubbing). Cheap, fast, does not fray, but weaker and less flexible: interfacing, masks, wipes, felt.
Smart and technical textiles
Technical textiles are made for performance, not looks: aramid fibres for fire-resistant and bullet-resistant wear, breathable membranes for waterproof jackets, geotextiles that hold soil on roadsides, and medical textiles such as bandages.
Smart textiles sense and react to changes around them:
- Thermochromic dyes change colour with temperature.
- Photochromic dyes change colour in sunlight.
- Phase-change materials store and release heat to keep the wearer comfortable.
- Microencapsulation: tiny capsules release scent, moisturiser or insect repellent.
- E-textiles: conductive yarns carry power or data, e.g. heart-rate sensors in sports shirts.
Try it
Take three old garments: a shirt, a T-shirt and a disposable mask. Pull each gently in both directions. Look at a cut edge with a magnifying glass. Which one has crossing yarns, which has loops, and which has random fibres? Rank them for stretch and for fraying.
Key formulas and definitions
- Fibre → yarn (spinning) → fabric (weaving, knitting, bonding)
- More twist = stronger, smoother, firmer yarn
- Blend = fibres mixed in one yarn; mixture = different yarns in one fabric
- Woven: warp (length) × weft (width), crossing at 90°
- Knitted: interlocking loops → stretch; non-woven: bonded fibre web
Worked examples
1. Why are sports leggings usually knitted and contain elastane?
Knitted loops let the fabric stretch with the body, and elastane fibres spring back so the leggings keep their shape. Polyester or nylon is often added for strength and quick drying.
2. A designer wants hard-wearing trousers for workers. Which construction and why?
A twill weave such as denim or drill. The diagonal over-two, under-two structure packs yarns tightly, so it is strong and resists abrasion. A polyester-cotton blend adds strength and reduces creasing while keeping comfort.
3. Why is felt used for hats and craft but not for stretchy clothes?
Felt is a non-woven made by locking wool fibres together. It does not fray and can be moulded into shapes, which suits hats. But it has no loops or yarns to give stretch and it tears more easily, so it is poor for close-fitting clothes.
Common mistakes
- Mixing up blend and mixture. A blend mixes fibres inside one yarn; a mixture uses different yarns in one fabric.
- Thinking warp runs across the fabric. Warp runs along the length, parallel to the selvedge.
- Saying non-wovens are made from yarns. They are made directly from fibres.
- Calling any high-performance fabric 'smart'. Smart textiles must react to a change; technical textiles just perform well.