Fibres and Fabrics
FoundationFibres are natural, regenerated or synthetic; cotton absorbs moisture, linen is strong but creases. Woven fabric is stable, knitted fabric stretches. Fibres are identified with a magnifier, strength and burn tests (teacher demonstration), guiding fabric choice and care.
- Fibre is the basic unit of fabric, grouped as natural, regenerated and synthetic
- Cotton absorbs moisture and washes well; linen is strong and crisp but creases
- Woven fabric is stable, knitted fabric stretches; read the care label first
文體小知識：生活科技說明文：把纖維布料的分類、特性和辨識方法說得條理分明，並清楚交代實驗的安全規範。
§Text Passage
1Every garment in the wardrobe comes down to tiny fibres. Fibres are spun into yarn, yarn is woven into fabric, and fabric is cut into clothes. Knowing fibre types and properties is the starting point of choosing, wearing and caring for clothing — the foundation of textiles work.
2By origin, fibres are natural, regenerated or synthetic: cotton and linen come from plants, wool and silk from animals, rayon is processed from wood pulp, and polyester and nylon are products of petrochemicals. Each has its own character — cotton absorbs and breathes, linen is strong but creases, polyester holds shape and dries fast.
3The same fibre can become different fabrics: woven cloth crosses warp and weft for stability, while knitted cloth interlocks loops for softness and stretch. Before caring for a garment, read its care label and follow the symbols for water temperature, ironing and drying, so clothes last longer.
4Simple classroom tests identify fibres: a magnifier shows texture, a strength test compares dry and wet performance, and the burn test — demonstrated by the teacher — shows plant fibres smelling of burning paper with soft ash, and synthetics shrinking into hard beads. With these methods, choosing and caring for fabric is evidence-based.
1Summary 重點摘要
Fibres are natural, regenerated or synthetic; cotton absorbs moisture, linen is strong but creases. Woven fabric is stable, knitted fabric stretches. Fibres are identified with a magnifier, strength and burn tests (teacher demonstration), guiding fabric choice and care.
2Vocabulary cards Vocabulary
The slender material spun into yarn and woven into cloth — the basic unit of all clothing.
Fibres from plants or animals, such as cotton, linen, wool and silk.
Fibres made from petrochemicals, such as polyester and nylon.
Fibres chemically processed from natural material such as wood pulp, e.g. rayon (viscose).
A plant fibre from cotton seeds: absorbent, breathable and washable, but prone to creasing and shrinking.
A stem fibre that is strong, crisp and cool, but creases very easily.
Cloth made by crossing warp and weft yarns; stable and shape-holding, like denim.
Cloth made of interlocking loops; stretchy, soft and close-fitting, like T-shirt fabric.
A simple test comparing the force needed to break fibres or yarns when dry and wet.
Identifying fibres by the smell and ash when they burn — teacher demonstration only.
3Step by step Steps
- From fibre to fabricFabrics are made from yarns, and yarns are spun from tiny fibres — fibre is the basic unit of all clothing. Knowing fibres explains why some clothes absorb sweat, some block wind and some crease easily, and lets you choose fabrics and care for them properly. For example, cotton school shirts feel cool in summer because cotton absorbs moisture well, while a polyester windbreaker is light and hard-wearing because synthetic fibres are strong. When designing a garment, the first step is matching fibre and fabric to the purpose.
- Three fibre familiesBy origin, fibres fall into three families: natural, regenerated and synthetic. Natural fibres split into plant fibres (cotton, linen) and animal fibres (wool, silk); regenerated fibres are chemically processed from natural material such as wood pulp, for example rayon (viscose); synthetic fibres are built from petrochemicals, commonly polyester and nylon. For example, socks labelled 70% cotton and 30% polyester blend a natural and a synthetic fibre — taking cotton's absorbent comfort plus polyester's shape and durability, the commonest formula in everyday clothing.
- Properties of cottonCotton comes from the fibres around cotton seeds and is the most used natural fibre. It absorbs moisture strongly, breathes well, feels gentle on skin, tolerates fairly hot washing and ironing, and actually grows stronger when wet, so it washes well; its weaknesses are low elasticity, easy creasing and shrinking. For example, in Hong Kong's humid summer a cotton school uniform still feels fresh after absorbing sweat, which is why schools choose cotton or cotton-blend uniforms; but pure cotton shirts need ironing to look crisp, and should be pulled flat while drying to reduce wrinkles.
- Properties of linenLinen comes from the stem of the flax plant and is one of the strongest natural fibres. It is crisper than cotton, releases heat and moisture quickly and feels cool, suiting hot weather; its drawbacks are a harder handle, very easy creasing, and weak elasticity that wears the fabric at fold lines. For example, summer linen shirts and tablecloths look cool and neat on the hanger yet wrinkle all over within half a day — not poor quality but the nature of linen; iron with higher heat and a water spray to restore flatness, and hang rather than fold it for storage.
- Weaves and careYarns become fabric in two main ways: woven fabric crosses warp and weft yarns at right angles and holds its shape, like denim and shirting; knitted fabric is built from interlocking loops, giving stretch and softness, like T-shirt and sportswear cloth. Before caring for any garment, read its care label: washing temperature, bleaching, ironing heat and dry-cleaning requirements are all shown there. For example, a woollen jumper washed in hot water shrinks drastically because wool fibres felt under heat and agitation; washing by hand in cold water and drying flat keeps its shape.
- Identifying fibresLessons use three simple identification methods. The magnifier shows cotton's naturally twisted, fuzzy fibres against the smooth, even look of synthetics. The strength test compares the force needed to break a yarn dry and wet — cotton is stronger wet, rayon weaker. The burn test must be demonstrated by the teacher in a well-ventilated, safe setting, with students observing and recording: cotton and linen burn quickly with a smell of burning paper and leave soft, crumbly ash; synthetics melt and shrink into hard beads with a chemical smell. Never attempt burning tests on your own at home.
- Choosing fabric by purposeThe first step of the basic design process is understanding the need, then choosing fabric by function, appearance, care requirements and cost: next-to-skin clothing values absorbency and breathability, so cotton dominates; sportswear values quick drying and stretch, so synthetic blends lead; tablecloths and curtains need washability and body, where cotton, linen or blends all work. For example, a class T-shirt in pure cotton loses shape after many washes and fades sooner; a cotton-polyester blend keeps the comfort and sweat absorption, holds its shape, prints sharper and costs less — purpose-driven fabric choice in action.
4Diagrams Diagrams
5Worked example Example
Example: two white fabric samples, A and B, sit on the bench. Using observation and the teacher's demonstrations, decide which is cotton and which is polyester.
- Magnifier: A shows naturally twisted, fuzzy fibres; B is smooth, even and shiny
- Teacher burns A: quick burning, a smell of burning paper, soft grey ash
- Teacher burns B: melting and shrinking into a hard black bead, with a plastic-like smell
- Strength test as support: A is even stronger when wet; B is much the same dry or wet
- Answer: A is cotton: naturally twisted fibres, a burning-paper smell and soft ash are classic plant-fibre signs, and extra strength when wet fits cotton too. B is polyester: smooth and shiny, melting into a hard bead — how synthetics behave under heat. Start with non-destructive observation, then the teacher's tests, and weigh all the evidence together rather than one sign alone; afterwards make sure everything is fully extinguished and cleared away.
6Common mistakes Mistakes
7Quick check Quick check
Q1Which is a synthetic fibre? A. cotton B. wool C. polyester
Q2Cotton suits Hong Kong summers. Name two properties of cotton behind this.
Q3What are the features of woven and knitted fabrics? Give one garment example of each.
Q4In the teacher's burn test, how do cotton and polyester differ in smell and residue?
Q5Why must you read the care label before washing a woollen knitted top?
8Recap Recap
- Fibre is the basic unit of fabric, grouped as natural, regenerated and synthetic
- Cotton absorbs moisture and washes well; linen is strong and crisp but creases
- Woven fabric is stable, knitted fabric stretches; read the care label first
- Fibres are identified by magnifier, strength test and burn test — burns are teacher demonstrations only
- Choosing fabric by purpose, care needs and cost is the first step of garment design