Physical properties of wool

Strength:

It is stronger than silk. When wet wool looses about 25% of its strength. Longer the fibre the greeter will be the strength of yarn.

Resiliency:

Wool is highly resilient and comes to its original shape when hanged after wrinkled or created

Stretchability:

Wool is highly elastic. It is about 10 to 30% stretched when dry and 40 to 50% when wet upon receiving pressure upon drying it readily regains its original dimensions. Shrink ability: Wool is resistant shrinkage. However long exposure to moisture may cause shrinkage.

Effect of friction:

Friction will soften the wool fibre especially when wet and thus is advantageous in maintaining smooth, soft texture of fabrics. Crimps: Wool fibre is more or less wavy and has twists. This waviness is termed as ‘crimp’. Finer the wool the more will be the crimps in it. Merino wool has 30 crimps per inch while coarse wool has one or two.

Effect of moisture:

Wool is the most hygroscopic in nature. It can absorb up to 50% of its weight and carry upto 20% weight, without giving the feeling of being wet. Upon drying it losses moisture slowly preventing rapid evaporation thus avoiding chilling feel to the user. It absorbs perspiration after violent exercise and guards the body against sudden change in temperature.

Heat conductivity:

Wool fibre is a part is a poor conductor of heat and therefore the fabrics made from the fibre are considered most suitable as winter wear.

Felting:

Wool fibres interlock and contract when exposed to heat, moisture, and pressure. The scale like exterior of the fibres contributes to felting. The fibres get softened in weak alkaline solutions due to expansion of scales at their free edges, with friction and pressure they again interlock to form a felt. This property is used in making felts for hats, shoes, floor-coverings and sound proofing purposes.

Effect of heat:

Low heat has no effect but strong heat weakens the fibre and destroys the colour of the fibre

Uses of wool

The majority of wool (72.8%) is used in apparel, home furnishing account for 15-45%, industrial uses 6 to 7% and exports 5%, wool accounts for 3.3% of all fibres for apparel. The most important use of wool is for apparel coats, jackets, suits, dresses, skirts, slacks made from woven fabrics of varying weights and knitted fabrics’.

All these gives the warmth garments and with good tailored look. In the home furnishing area the major use of wool is in carpets and rugs where wool is used more, cover to the carpets and warm in the rugs. Blends of different synthetic fibres with wool for suiting materials are increasingly important. This result in fabrics that are more appropriate in warmer conditions. Polyester is the most important fibre used in blending with wool.