Learning Objectives
- Learn about animal fibres - wool and silk
- Understand the processing of wool
- Know about sericulture and silk production
- Understand the life cycle of silk moth
Key Concepts
Animal Fibres
Fibres obtained from animals:
- Wool: Obtained from fleece (hair) of sheep, goat, yak, camel, llama, alpaca
- Silk: Obtained from cocoons of silk moth (silkworm)
Wool
Sources of wool: Sheep (most common), Angora goat (mohair), Pashmina goat (cashmere), Yak (yak wool), Camel, Llama, Alpaca.
Processing of wool:
- Shearing: Removing fleece from sheep (done in summer, doesn't hurt sheep as hair grows back)
- Scouring: Washing sheared skin in tanks to remove grease and dirt
- Sorting: Separating different textures of hair
- Picking out burrs: Removing small fibres and fluffy fibres
- Dyeing: Colouring fibres in desired colours
- Rolling: Straightened fibres rolled into yarn
Silk
Sericulture: The rearing of silkworms to obtain silk.
Life cycle of silk moth: Egg → Larva (caterpillar/silkworm) → Pupa (cocoon stage) → Adult moth
Silk production:
- Female silk moth lays eggs on mulberry leaves
- Eggs hatch into larvae (silkworms) that feed on mulberry leaves
- Silkworm spins a cocoon around itself using silk fibre from its salivary glands
- Cocoons are collected and boiled in water to kill pupa and soften silk
- Silk fibres are unwound from cocoon (reeling)
- Fibres twisted together to form silk thread
Discovery of Silk
Silk was discovered in China around 3000 BC. China kept the secret of silk production for centuries. The trade route from China was called the Silk Route.
Summary
Wool comes from sheep and other animals through shearing, scouring, sorting, and spinning. Silk comes from silkworm cocoons through sericulture. The silkworm goes through four stages of life cycle. Silk production involves rearing silkworms on mulberry leaves and reeling silk from cocoons.
Important Terms
- Shearing: Cutting off wool from sheep
- Scouring: Washing wool to remove dirt and grease
- Sericulture: Rearing silkworms for silk
- Cocoon: Protective covering spun by silkworm
- Reeling: Pulling silk fibres from cocoon
Quick Revision
- Wool: Sheep → Shearing → Scouring → Sorting → Dyeing → Yarn
- Silk moth life cycle: Egg → Larva → Pupa (cocoon) → Adult moth
- Sericulture = rearing silkworms for silk
- Silkworm feeds on mulberry leaves
- Silk discovered in China ~3000 BC, Silk Route