Animal fiber-Wool

3
Wool: Wool is the fiber derived from the hair of domesticated animals, usually sheep. Wool is classified according to the source from which it is obtained. The fleece or the wool which is collected is kept to the different stages of manufacturing process which starts with the preparation of the fiber. The different stage through which it is taken depends upon whether the fiber is intended for worsted or woolen yarns. The flow chart for the manufacturing process is as follows: Preparation Wool Fleeces vary from 6 to 18 pounds (3-8 kg) in weight. The best quality wool is obtained from the sides and shoulders and is treated as one fleece. Similarly, the wool obtained from the head, chest, belly, and shanks is treated as a second fleece. 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 from 20 to 80 percent of its original weight. The wool obtained should be carefully sorted into different grades. Sorting and Grading: Insorting, the wool is broken up into sections of different quality fibers, from different parts of the body. The best quality of wool or one fleece is used for clothing; the lesser quality or second fleece is used to make rugs. Each grade is determined by type, length, fineness, elasticity, and strength. The wool may be graded according to the type of merino sheep or according to fineness or diameter which is otherwise called as United States System and British System. The classification according to the United States System or according to the type of merino sheep from which it is obtained is as follows: First quality wool is identified as fine and is equivalent to the quality of wool that could be obtained from a full- to three-quarter-blood Merino sheep.

description

wool fiber

Transcript of Animal fiber-Wool

Wool:Woolis the fiber derived fromthe hair of domesticated animals, usually sheep. Wool is classifiedaccording to the source from which it is obtained. The fleece or thewool which is collected is kept to the different stages of manufacturing processwhich starts with the preparation of the fiber. The differentstage through which it is taken depends upon whether the fiber is intended for worsted or woolen yarns. The flow chart for the manufacturing process is as follows:Preparation WoolFleecesvary from 6 to 18 pounds (3-8 kg) in weight. The best quality wool isobtained from the sides and shoulders and is treated as one fleece.Similarly, the wool obtained from the head, chest, belly, and shanks istreated as a second fleece.Theraw wool or newly sheared fleece is called grease wool because itcontains the natural oil of the sheep. When grease wool is washed, itloses from 20 to 80 percent of its original weight. The wool obtainedshould be carefully sorted into different grades.

Sorting and Grading:Insorting, the wool is broken up into sections of different qualityfibers, from different parts of the body. The best quality of wool orone fleece is used for clothing; the lesser quality or second fleece isused to make rugs. Each grade is determined by type, length, fineness,elasticity, and strength. The wool may be graded according to the typeof merino sheep or according to fineness or diameter which is otherwisecalled as United States System and British System.

Theclassification according to the United States System or according to thetype of merino sheep from which it is obtained is as follows: First quality wool is identified as fine and is equivalent to thequality of wool that could be obtained from a full-tothree-quarter-blood Merino sheep. Second quality is equivalent to the kind of wool that could be obtained from a half blood Merino. Thepoorest qualities are identified as common and braid; they are coarse,have little crimp, relatively few scales and are somewhat hair like inappearance. The grading system on the world market is based uponthe British numbering system, which relates the fineness, or diameter,of the wool fiber to the kind of combed, or worsted, yarn that could bespun from 1 pound of scoured wool. The first in quality would bethat wool which is fine enough for and capable of being spun into thehighest wool yarn counts of 80s, 70s, and 64s (No. of 560 yards in 1pound). The second quality is fine enough to be capable of being spun into yarn counts of 62s, 60s, and 58s. The poorest grade is capable of being spun into yarn counts of only 40s and 30s.Comparative Wool Grading TableUnited States SystemBritish System

Fine (full-to-three-quarter-blood)80S, 70S, 64S

Half blood62S, 60S, 58S

Three eights blood56S

Quarter blood50S, 48S

Low quarter blood46S

Common44S

Braid40S, 36S

Scouring:Wool takendirectly from the sheep is called "raw" or "grease wool." It containssand, dirt, grease, and dried sweat. The weight of these contaminantsaccounts for about 30 to 70 percent of the fleeces total weight.

Woolscouring is the first step in the conversion of greasy wool into atextile product. It is the process of washing wool in hot water anddetergent to remove the non-wool contaminants and then drying it. Thescouring machine contains warm water, soap and a mild solution of sodaash or other alkali. They are equipped with automatic rakes, which stirthe wool. Rollers between the vats squeeze out the water. If the rawwool is not sufficiently clear of vegetable substance after scoring, itis put through the carbonizing bath of dilute sulfuric acid orhydrochloric acid to burn out the foreign matter.

Drying:Woolafter scouring should not be allowed to become absolutely dry. About,12 to16 percent of the moisture is left in the wool which would enablehandling of the fibers in further processing.

Oiling:Woolis unmanageable after scouring and hence the fiber requires to betreated with various oils to keep it from becoming brittle. Oiling ofthe fibers also helps to lubricate it for the spinning operation.

Carding:From this stage, further processing depends on whether woolen orworsted yarns are to be produced. The main objective of carding is todisentangle and to open the scoured wool. Carding also forms a web ofdisentangled fibers that are formed into sliver.