WOOL FIBRE: PART 2

WOOL FIBRE: PART 2

WOOL FIBRE

PHYSICAL PROPERTIES OF WOOL FIBRE:

• LENGTH:

Length of wool fibre varies from 3.6-35 cm.

Fine wool= 3.2-10 cm

Medium wool= 5-20 cm

Coarse wool= 15 cm and more

• FINENESS:

Fineness of wool fibre is directly proportional with the length of a fibre.
Fineness is ranges from 10-70 microns
Carpet wool= 20-70 microns
Merino wool= 10-30 microns

• CROSS-SECTION:

The cross-section of wool fibre are varies sometimes they are circular and sometimes they are elliptical.
Longitudinal: rod like with scales

• CRIMP:

Crimp of wool fibre is varies from 0-30 crimps per inch.
Fine wool= 14-22 crimps/inch
Medium wool= 8-14 crimps/inch
Coarse wool= up to 8 crimps/inch

• STRENGTH:

Breaking strength= 4.8-7.1 gms
Medium fibre= 10-16 gms
Coarse fibre= 20-24 gms

• COLOUR:

The colour of wool fibre is mostly black. Sometimes it is yellowish, may be black to brown.

• ELONGATION:

Elongation= 25-35%

• MOISTURE REGAIN:

R.H 70-80%= 15-18%
R.H 55-60%= 12-15%

• SPECIFIC GRAVITY:

Specific Gravity= 1.3-1.32 g/cc.

• ELASTICITY:

Wool having the best Elasticity. Within a less load applied on it, it elongate more.
Elasticity= 90-92%

CHEMICAL PROPERTIES OF WOOL FIBRE:

• ACTION OF HEAT:

Heated in dry air at 100-110 DegreeC for a long period it loses its moisture. Fibre become harsh and lose its strength. Decompose and turns yellow colour.

• EFFECT OF WATER AND STEAM:

Exposed to water and steam with or without tension. Wool will change in its shape and its affinity to dye.

• EFFECT OF ACIDS:

With HCL and H2SO4 at high concentration wool is hydrolyzed immediately and salt is formed with amino compounds which gradually dissolve in acid medium. The colour becomes yellow to deep yellow and fibre become brittle hard and losses all properties.

• EFFECT OF ALKALIES:

5% NaOH ( caustic soda) at boil solvent dissolves completely. Disintegration with dilute NaOH

• EFFECT OF SALTS:

Ca and Mg salts in hard water causes a yellowing effect on prolonged boiling.

• ACTION OF OXIDIZING AGENT:

Damage wool more or less depending on temperature concentration and pH.

APPLICATION OF WOOL:

Clothing.
Jackets.
Home decoration.
Blankets.
Insulations.
Upholstery.
Suits, Felts, Carpeting.
Soil Fertilizers.

• Published By:

Vaishnavi Pandhare.

Dept. Of Textile Technlogy,

DKTE Textile and Engineering Institute,Ichalkaranji.