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Wool
- 1. Fiber to Fabric Dr.Ritu Madhan
- 2. Originally, wool wasborne on wild species of sheep as a short, fluffy undercoat concealed by hair. When wild sheep were killed by primitive people for food, they used the felts as body covering. The fluffy undercoats probably become matted by usage, thus giving early man an idea of felting it into a crude cloth. It is believed that ancient shepherds in the first century AD. discovered that Merino sheep could be bred to improve the fleece.
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- 7. Insufficient / poor quality food Growth retardation/ poor fibers
- 8. Merino • Outstanding quality •Length ranges from 1- 5” • Fiber is strong, fine and elastic • Fibers have maximum crimp of all wool fibers • Maximum numbers of scales i.e., 3000/” Class two • Fibers not as good as Merino wool • It is 2-8” in length • Has a large number of scales per inch and has a good crimp. • The fibers are strong, fine and elastic
- 9. Class three •Fibers areabout 4-18” •Fibers are long, coarse •Fibers have fewer scales and less crimp •The fibers are smoother and have more luster. •These fibers are less elastic and resilient Class four •The fibers are from 1- 16” •Fibers are long, coarse and hair-like, have relatively few scales and low crimp •Fibers are smoother and lustrous. •Least elasticity and strength
- 10. • When thesheep is 6 – 8 months old Lambs wool • When the sheep is 12 – 14 months old Hogget wool • When the sheep is 14 months • Second shearing, contains dirt and oil Wether wool
- 11. • When thesheep is slaughtered for their meat Pulled wool • When the sheep dies an accidental / natural death • Quality is inferior Dead wool • From sheep exposed to severe weather / diet conditions Cotty wool • Discolored parts of wool from any of the above, inferior quality Taglocks
- 12. Fleeces vary from6-18 lbs (3-8 kg)in weight and ultimately provide about 3 lbs (1.5kg) of scoured wool the fleece is packed in sacks Domestic wool reaches the mill in loosely packed bags and imported wool reaches the mill in the form of bales. Each fleece contains different grades or sorts, of wool and raw stock must be carefully graded according to length, diameter and quality of fiber. The raw wool or newly sheared fleece is called grease wool because it contains the natural oil of the sheep. When grease wool is washed; it loses 20-80 of it original weight.
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- 14. Done by skilled workerson the basis of touch and sight Length, fineness, elasticity & strength
- 15. Recycled wool fibersare obtained separately by reducing the used materials to a fibrous mass by a picking and shredding process called garneting. The fibers are then put through a dilute solution of H2SO4 or HCL acid, which destroys any vegetable matter The quality and the cost of recycled wool fibers depend on the original stock from which they are obtained. A good quality of recycled wool may cost as much as 5 times as a poor grade of virgin wool.
- 16. The next stepin preparing raw wool for manufacturing is a thorough washing in an alkaline solution, this process is known as scouring. The scouring machines contain warm water, soap, and a mild solution of soda ash or other alkali. The machine is equipped with automatic rakes which stir the wool.
- 17. • Wool isnot allowed to become absolutely dry. • Usually 12 -18 % moisture is left in the wool to condition it for subsequent handling. Drying • As wool is unmanageable after scouring the fiber is usually treated with various oils, to keep it from becoming brittle and to lubricate it for the spinning operations. Oiling
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- 19. • Can bedone at fiber stage, yarn stage or fabric stage Dyeing • Different grades of wool or different fibers are blended Blending • Disentangle- ment and removal of short length fibers Carding
- 20. Combing • Further aligning fibers • Usingonly superior fibers Drawing • Doubling and redoubling of slivers Roving • Imparting slight twist to decrease diameter of slivers
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- 25. Scales on thesurface Serrated / rough surface Root end is angular Central canal – Medulla
- 26. Linear molecule Composed of keratin Made upof amino acids Helical configuration
- 27. Irreversible shrinkage ofthe length , breadth and /or thickness of the material. Wool felts because of the serrated surface of its fibers which is formed by the overlapping epithelial cells or scales. Because of this serrated structure, less friction will result if the fiber moves in a root ward direction than if it moves in tip ward direction
- 28. This difference insurface friction between the two directions known as the directional friction effect (DFE). The root end of the fiber curls upon itself. This movement caused by agitation and moisture, is due to DFE of the wool fiber’s surface. Felting is increased by the action of heat, moisture & pressure
- 29. • Poor Luster • Leastin all natural fibers • Loses strength when wet Strength • Good Elasticity • Good Resilience • Good Drapability • 1.31 Specific Density
- 30. • Initially waterrepellent, but once moisture seeps in, readily absorbs moisture • Absorbs 20% of its weight Moisture • Wool becomes harsh at 212°F (100°C) and begins to decompose at slightly higher temperatures. It will scorch at 400°F (204°C) and will eventually char. However it is not easily combustible Thermal
- 31. Alkalies • Damaged by strong alkalies Acids •Damaged by conc H2SO4 • Not affected by others Bleaches • Harmful for the fabric Biological • Not affected by mildew • Affected by larvae of moth & other insects
- 32. Dirt and odorsretained , needs frequent laundering Care to be taken , use neutral detergents, do not wring, squeeze or pull fabrics out of water Wash in cold water, flat dry the garment to avoid stretching / shrinking