Wool is extracted from sheep. There are various types of wool. Marino wool is the best wool.

Physical properties:

1. Length: length of wool fibre varies from 2 to 12 depending on type of fibre and the interval length of time of collection.

2. Fineness: normally longer the fibre coarser the fibre fineness varies from 3-15 dtex that is coarser than cotton fibre.

3. Strength & extension: wool is weak fibre, its tenacity is 1 to 1.5 g/dtex & break 35%.

4. Elastic property: wool is the best natural fibre in respect of good recovery from deformation.

5. Cross-sectional shape: roughly circular or elliptical in cross-section.

6. Appearance: characterized by crimp & scales. Due to scales and extensibility its felling property is good. Color varies depending on type of wool fibre.

7. Effect of chemical:

· Water: moisture regain of wool is 19% & when wet strength reduces about 20%.

· Alkali: alkali degrades the wool fibre, changes color & reduces strength.

· Acid: wool is safe in acid. In carbonizing wool 5% sulphuric acid solution is used to remove vegetable & cellulosic materials.

· Solvent: wool is safe in solvent, hence dry-cleaning is popular for woolen garments.

8. Effect of heat: burns with burning hair smell with specific sound.

9. End use: area of use depends on variety of wool.e.g.

· Merino: suiting dress materials

· Fine cross bread: blanket, knitwear, linht wear outings.

· Coarse cross bread: blanket, tweed, carpet.

· Carpet wool carpet, rags etc.